diff --git a/package-lock.json b/package-lock.json
index b927fc5..cbac198 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,6 +1,6 @@
 {
   "name": "c3",
-  "version": "0.4.20",
+  "version": "0.4.21",
   "lockfileVersion": 1,
   "requires": true,
   "dependencies": {
@@ -21,6 +21,21 @@
         }
       }
     },
+    "@types/acorn": {
+      "version": "4.0.3",
+      "resolved": "https://registry.npmjs.org/@types/acorn/-/acorn-4.0.3.tgz",
+      "integrity": "sha512-gou/kWQkGPMZjdCKNZGDpqxLm9+ErG/pFZKPX4tvCjr0Xf4FCYYX3nAsu7aDVKJV3KUe27+mvqqyWT/9VZoM/A==",
+      "dev": true,
+      "requires": {
+        "@types/estree": "0.0.38"
+      }
+    },
+    "@types/estree": {
+      "version": "0.0.38",
+      "resolved": "https://registry.npmjs.org/@types/estree/-/estree-0.0.38.tgz",
+      "integrity": "sha512-F/v7t1LwS4vnXuPooJQGBRKRGIoxWUTmA4VHfqjOccFsNDThD5bfUNpITive6s352O7o384wcpEaDV8rHCehDA==",
+      "dev": true
+    },
     "JSONStream": {
       "version": "1.3.2",
       "resolved": "https://registry.npmjs.org/JSONStream/-/JSONStream-1.3.2.tgz",
@@ -53,6 +68,23 @@
       "integrity": "sha1-EFSVrlNh1pe9GVyCUZLhrX8lN4c=",
       "dev": true
     },
+    "acorn-dynamic-import": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/acorn-dynamic-import/-/acorn-dynamic-import-3.0.0.tgz",
+      "integrity": "sha512-zVWV8Z8lislJoOKKqdNMOB+s6+XV5WERty8MnKBeFgwA+19XJjJHs2RP5dzM57FftIs+jQnRToLiWazKr6sSWg==",
+      "dev": true,
+      "requires": {
+        "acorn": "5.5.3"
+      },
+      "dependencies": {
+        "acorn": {
+          "version": "5.5.3",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.5.3.tgz",
+          "integrity": "sha512-jd5MkIUlbbmb07nXH0DT3y7rDVtkzDi4XZOUVWAer8ajmF/DTSSbl5oNFyDOl/OXA33Bl79+ypHhl2pN20VeOQ==",
+          "dev": true
+        }
+      }
+    },
     "acorn-node": {
       "version": "1.3.0",
       "resolved": "https://registry.npmjs.org/acorn-node/-/acorn-node-1.3.0.tgz",
@@ -2202,6 +2234,15 @@
       "integrity": "sha1-6vQ5/U1ISK105cx9vvIAZyueNFs=",
       "dev": true
     },
+    "date-time": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/date-time/-/date-time-2.1.0.tgz",
+      "integrity": "sha512-/9+C44X7lot0IeiyfgJmETtRMhBidBYM2QFFIkGa0U1k+hSyY87Nw7PY3eDqpvCBm7I3WCSfPeZskW/YYq6m4g==",
+      "dev": true,
+      "requires": {
+        "time-zone": "1.0.0"
+      }
+    },
     "debug": {
       "version": "2.6.9",
       "resolved": "https://registry.npmjs.org/debug/-/debug-2.6.9.tgz",
@@ -4909,6 +4950,15 @@
       "integrity": "sha1-HQPd7VO9jbDzDCbk+V02/HyH3CQ=",
       "dev": true
     },
+    "is-reference": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/is-reference/-/is-reference-1.1.0.tgz",
+      "integrity": "sha512-h37O/IX4efe56o9k41II1ECMqKwtqHa7/12dLDEzJIFux2x15an4WCDb0/eKdmUgRpLJ3bR0DrzDc7vOrVgRDw==",
+      "dev": true,
+      "requires": {
+        "@types/estree": "0.0.38"
+      }
+    },
     "is-retry-allowed": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/is-retry-allowed/-/is-retry-allowed-1.1.0.tgz",
@@ -5592,6 +5642,12 @@
         "strip-bom": "2.0.0"
       }
     },
+    "locate-character": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmjs.org/locate-character/-/locate-character-2.0.5.tgz",
+      "integrity": "sha512-n2GmejDXtOPBAZdIiEFy5dJ5N38xBCXLNOtw2WpB9kGh6pnrEuKlwYI+Tkpofc4wDtVXHtoAOJaMRlYG/oYaxg==",
+      "dev": true
+    },
     "locate-path": {
       "version": "2.0.0",
       "resolved": "https://registry.npmjs.org/locate-path/-/locate-path-2.0.0.tgz",
@@ -7088,6 +7144,12 @@
         "error-ex": "1.3.1"
       }
     },
+    "parse-ms": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/parse-ms/-/parse-ms-1.0.1.tgz",
+      "integrity": "sha1-VjRtR0nXjyNDDKDHE4UK75GqNh0=",
+      "dev": true
+    },
     "parseqs": {
       "version": "0.0.5",
       "resolved": "https://registry.npmjs.org/parseqs/-/parseqs-0.0.5.tgz",
@@ -7278,6 +7340,16 @@
       "integrity": "sha1-gV7R9uvGWSb4ZbMQwHE7yzMVzks=",
       "dev": true
     },
+    "pretty-ms": {
+      "version": "3.1.0",
+      "resolved": "https://registry.npmjs.org/pretty-ms/-/pretty-ms-3.1.0.tgz",
+      "integrity": "sha1-6crJx2v27lL+lC3ZxsQhMVOxKIE=",
+      "dev": true,
+      "requires": {
+        "parse-ms": "1.0.1",
+        "plur": "2.1.2"
+      }
+    },
     "private": {
       "version": "0.1.8",
       "resolved": "https://registry.npmjs.org/private/-/private-0.1.8.tgz",
@@ -7781,6 +7853,12 @@
       "integrity": "sha1-l/cXtp1IeE9fUmpsWqj/3aBVpNE=",
       "dev": true
     },
+    "require-relative": {
+      "version": "0.8.7",
+      "resolved": "https://registry.npmjs.org/require-relative/-/require-relative-0.8.7.tgz",
+      "integrity": "sha1-eZlTn8ngR6N5KPoZb44VY9q9Nt4=",
+      "dev": true
+    },
     "requires-port": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/requires-port/-/requires-port-1.0.0.tgz",
@@ -7832,10 +7910,47 @@
       }
     },
     "rollup": {
-      "version": "0.55.5",
-      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.55.5.tgz",
-      "integrity": "sha512-2hke9NOy332kxvnmMQOgl7DHm94zihNyYJNd8ZLWo4U0EjFvjUkeWa0+ge+70bTg+mY0xJ7NUsf5kIhDtrGrtA==",
-      "dev": true
+      "version": "0.57.1",
+      "resolved": "https://registry.npmjs.org/rollup/-/rollup-0.57.1.tgz",
+      "integrity": "sha512-I18GBqP0qJoJC1K1osYjreqA8VAKovxuI3I81RSk0Dmr4TgloI0tAULjZaox8OsJ+n7XRrhH6i0G2By/pj1LCA==",
+      "dev": true,
+      "requires": {
+        "@types/acorn": "4.0.3",
+        "acorn": "5.5.3",
+        "acorn-dynamic-import": "3.0.0",
+        "date-time": "2.1.0",
+        "is-reference": "1.1.0",
+        "locate-character": "2.0.5",
+        "pretty-ms": "3.1.0",
+        "require-relative": "0.8.7",
+        "rollup-pluginutils": "2.0.1",
+        "signal-exit": "3.0.2",
+        "sourcemap-codec": "1.4.1"
+      },
+      "dependencies": {
+        "acorn": {
+          "version": "5.5.3",
+          "resolved": "https://registry.npmjs.org/acorn/-/acorn-5.5.3.tgz",
+          "integrity": "sha512-jd5MkIUlbbmb07nXH0DT3y7rDVtkzDi4XZOUVWAer8ajmF/DTSSbl5oNFyDOl/OXA33Bl79+ypHhl2pN20VeOQ==",
+          "dev": true
+        },
+        "estree-walker": {
+          "version": "0.3.1",
+          "resolved": "https://registry.npmjs.org/estree-walker/-/estree-walker-0.3.1.tgz",
+          "integrity": "sha1-5rGlHPcpJSTnI3wxLl/mZgwc4ao=",
+          "dev": true
+        },
+        "rollup-pluginutils": {
+          "version": "2.0.1",
+          "resolved": "https://registry.npmjs.org/rollup-pluginutils/-/rollup-pluginutils-2.0.1.tgz",
+          "integrity": "sha1-fslbNXP2VDpGpkYb2afFRFJdD8A=",
+          "dev": true,
+          "requires": {
+            "estree-walker": "0.3.1",
+            "micromatch": "2.3.11"
+          }
+        }
+      }
     },
     "rollup-plugin-babel": {
       "version": "3.0.3",
@@ -8324,6 +8439,12 @@
       "integrity": "sha1-PpNdfd1zYxuXZZlW1VEo6HtQhKM=",
       "dev": true
     },
+    "sourcemap-codec": {
+      "version": "1.4.1",
+      "resolved": "https://registry.npmjs.org/sourcemap-codec/-/sourcemap-codec-1.4.1.tgz",
+      "integrity": "sha512-hX1eNBNuilj8yfFnECh0DzLgwKpBLMIvmhgEhixXNui8lMLBInTI8Kyxt++RwJnMNu7cAUo635L2+N1TxMJCzA==",
+      "dev": true
+    },
     "spdx-correct": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/spdx-correct/-/spdx-correct-1.0.2.tgz",
@@ -8750,6 +8871,12 @@
       "dev": true,
       "optional": true
     },
+    "time-zone": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/time-zone/-/time-zone-1.0.0.tgz",
+      "integrity": "sha1-mcW/VZWJZq9tBtg73zgA3IL67F0=",
+      "dev": true
+    },
     "timed-out": {
       "version": "4.0.1",
       "resolved": "https://registry.npmjs.org/timed-out/-/timed-out-4.0.1.tgz",