adding popularity to sort scoring function list

query/sort.js

@@ -1,4 +1,5 @@
 var population = 'population';
+var popularity = 'popularity';
 var weights = require('pelias-suggester-pipeline').weights;
 
 module.exports = [
@@ -9,6 +10,13 @@ module.exports = [
       'order': 'desc'
     }
   },
+  {
+    '_script': {
+      'file': popularity,
+      'type': 'number',
+      'order': 'desc'
+    }
+  },
   {
     '_script': {
       'params': {

test/unit/query/reverse.js

@@ -1,5 +1,7 @@
 
 var generate = require('../../../query/reverse');
+var population = 'population';
+var popularity = 'popularity';
 var weights = require('pelias-suggester-pipeline').weights;
 
 module.exports.tests = {};
@@ -15,7 +17,14 @@ var sort = [
   '_score',
   {
     '_script': {
-      'file': 'population',
+      'file': population,
+      'type': 'number',
+      'order': 'desc'
+    }
+  },
+  {
+    '_script': {
+      'file': popularity,
       'type': 'number',
       'order': 'desc'
     }

test/unit/query/search.js

@@ -1,5 +1,7 @@
 
 var generate = require('../../../query/search');
+var population = 'population';
+var popularity = 'popularity';
 var weights = require('pelias-suggester-pipeline').weights;
 
 module.exports.tests = {};
@@ -15,7 +17,14 @@ var sort = [
   '_score',
   {
     '_script': {
-      'file': 'population',
+      'file': population,
+      'type': 'number',
+      'order': 'desc'
+    }
+  },
+  {
+    '_script': {
+      'file': popularity,
       'type': 'number',
       'order': 'desc'
     }

test/unit/query/sort.js

@@ -1,6 +1,7 @@
 
 var generate = require('../../../query/sort');
 var population = 'population';
+var popularity = 'popularity';
 var weights = require('pelias-suggester-pipeline').weights;
 
 module.exports.tests = {};
@@ -20,6 +21,13 @@ var expected = [
       'order': 'desc'
     }
   },
+  {
+    '_script': {
+      'file': popularity,
+      'type': 'number',
+      'order': 'desc'
+    }
+  },
   {
     '_script': {
       'params': {