Swapping out `range` for underscore version

app.js

@@ -5,6 +5,7 @@ const http = require('http');
 const express = require('express');
 const app = express();
 const nunjucks = require('nunjucks');
+const _ = require('underscore');
 
 const env = new nunjucks.Environment(new nunjucks.FileSystemLoader(path.join(__dirname, 'views')));
 env.express(app);
@@ -28,27 +29,7 @@ app.use(function(req, res, next) {
 app.use(function(req, res, next) {
   // This should be in Nunjucks, but right now it's not
   // https://github.com/jlongster/nunjucks/issues/72
-  res.locals.range = function(start, stop, step) {
-    if (!step) step = 1;
-    if (!stop) {
-      stop = start;
-      start = 0;
-    }
-
-    var arr = [start];
-
-    if (start > stop) {
-      while (start - step > stop) {
-        arr.push(start -= step);
-      }
-    } else {
-      while (start + step < stop) {
-        arr.push(start += step);
-      }
-    }
-
-    return arr;
-  }
+  res.locals.range = _.range;
   next();
 })