Fix lint

c3.js

@@ -677,7 +677,6 @@ c3_axis_fn.updateXAxisTickValues = function updateXAxisTickValues(targets, axis)
 c3_axis_fn.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
     var $$ = this.owner,
         config = $$.config,
-        d3 = $$.d3,
         axisParams = {
         withOuterTick: withOuterTick,
         withoutTransition: withoutTransition,

spec/shape.bar-spec.js

@@ -1,5 +1,3 @@
-var setMouseEvent = window.setMouseEvent;
-
 describe('c3 chart shape bar', function () {
     'use strict';
 

src/axis.js

@@ -452,7 +452,7 @@ c3_axis_fn.updateXAxisTickValues = function updateXAxisTickValues(targets, axis)
     return tickValues;
 };
 c3_axis_fn.getYAxis = function getYAxis(scale, orient, tickFormat, tickValues, withOuterTick, withoutTransition, withoutRotateTickText) {
-    var $$ = this.owner, config = $$.config, d3 = $$.d3,
+    var $$ = this.owner, config = $$.config,
         axisParams = {
             withOuterTick: withOuterTick,
             withoutTransition: withoutTransition,