Update and rename Gruntfile.js to Gruntfile.coffee

Why? It's more pythonic in nature and grunt supports it by default!

Why not? Not everyone knows it! but it's no excuse to not use it. 
It's simple to understand/learn.

{{cookiecutter.repo_name}}/Gruntfile.coffee

@@ -0,0 +1,78 @@
+module.exports = (grunt) ->
+  appConfig = grunt.file.readJSON("package.json")
+
+  # Load grunt tasks automatically
+  # see: https://github.com/sindresorhus/load-grunt-tasks
+  require("load-grunt-tasks")(grunt)
+
+  # Time how long tasks take. Can help when optimizing build times
+  # see: https://npmjs.org/package/time-grunt
+  require("time-grunt")(grunt)
+  pathsConfig = (appName) ->
+    @app = appName or appConfig.name
+    app: @app
+    templates: @app + "/templates"
+    css: @app + "/static/css"
+    sass: @app + "/static/sass"
+    fonts: @app + "/static/fonts"
+    images: @app + "/static/images"
+    js: @app + "/static/js"
+    manageScript: @app + "/manage.py"
+
+  grunt.initConfig
+    paths: pathsConfig()
+    pkg: appConfig
+
+    # see: https://github.com/gruntjs/grunt-contrib-watch
+    watch:
+      gruntfile:
+        files: ["Gruntfile.coffee"]
+
+      compass:
+        files: ["<%= paths.sass %>/**/*.{scss,sass}"]
+        tasks: ["compass:server"]
+
+      livereload:
+        files: [
+          "<%= paths.js %>/**/*.js"
+          "<%= paths.sass %>/**/*.{scss,sass}"
+          "<%= paths.app %>/**/*.html"
+        ]
+        options:
+          spawn: false
+          livereload: true
+
+
+    # see: https://github.com/gruntjs/grunt-contrib-compass
+    compass:
+      options:
+        sassDir: "<%= paths.sass %>"
+        cssDir: "<%= paths.css %>"
+        fontsDir: "<%= paths.fonts %>"
+        imagesDir: "<%= paths.images %>"
+        relativeAssets: false
+        assetCacheBuster: false
+        raw: "Sass::Script::Number.precision = 10\n"
+
+      dist:
+        options:
+          environment: "production"
+
+      server:
+        options: {}
+
+    # see: https://npmjs.org/package/grunt-bg-shell
+    bgShell:
+      _defaults:
+        bg: true
+
+      runDjango:
+        cmd: "python <%= paths.manageScript %> runserver"
+
+  grunt.registerTask "serve", [
+    "bgShell:runDjango"
+    "watch"
+  ]
+  grunt.registerTask "build", ["compass:dist"]
+  grunt.registerTask "default", ["build"]
+  return

{{cookiecutter.repo_name}}/Gruntfile.js

@@ -1,101 +0,0 @@
-module.exports = function (grunt) {
-
-  var appConfig = grunt.file.readJSON('package.json');
-
-  // Load grunt tasks automatically
-  // see: https://github.com/sindresorhus/load-grunt-tasks
-  require('load-grunt-tasks')(grunt);
-
-  // Time how long tasks take. Can help when optimizing build times
-  // see: https://npmjs.org/package/time-grunt
-  require('time-grunt')(grunt);
-
-  var pathsConfig = function (appName) {
-    this.app = appName || appConfig.name;
-
-    return {
-      app: this.app,
-      templates: this.app + '/templates',
-      css: this.app + '/static/css',
-      sass: this.app + '/static/sass',
-      fonts: this.app + '/static/fonts',
-      images: this.app + '/static/images',
-      js: this.app + '/static/js',
-      manageScript: this.app + '/manage.py'
-    }
-  };
-
-  grunt.initConfig({
-
-    paths: pathsConfig(),
-    pkg: appConfig,
-
-    // see: https://github.com/gruntjs/grunt-contrib-watch
-    watch: {
-      gruntfile: {
-        files: ['Gruntfile.js']
-      },
-      compass: {
-        files: ['<%= paths.sass %>/**/*.{scss,sass}'],
-        tasks: ['compass:server']
-      },
-      livereload: {
-        files: [
-          '<%= paths.js %>/**/*.js',
-          '<%= paths.sass %>/**/*.{scss,sass}',
-          '<%= paths.app %>/**/*.html'
-          ],
-        options: {
-          spawn: false,
-          livereload: true,
-        },
-      },
-    },
-
-    // see: https://github.com/gruntjs/grunt-contrib-compass
-    compass: {
-      options: {
-          sassDir: '<%= paths.sass %>',
-          cssDir: '<%= paths.css %>',
-          fontsDir: '<%= paths.fonts %>',
-          imagesDir: '<%= paths.images %>',
-          relativeAssets: false,
-          assetCacheBuster: false,
-          raw: 'Sass::Script::Number.precision = 10\n'
-      },
-      dist: {
-        options: {
-          environment: 'production'
-        }
-      },
-      server: {
-        options: {
-          // debugInfo: true
-        }
-      }
-    },
-
-    // see: https://npmjs.org/package/grunt-bg-shell
-    bgShell: {
-      _defaults: {
-        bg: true
-      },
-      runDjango: {
-        cmd: 'python <%= paths.manageScript %> runserver'
-      }
-    }
-  });
-
-  grunt.registerTask('serve', [
-    'bgShell:runDjango',
-    'watch'
-  ]);
-
-  grunt.registerTask('build', [
-    'compass:dist'
-  ]);
-
-  grunt.registerTask('default', [
-    'build'
-  ]);
-};