Remove imagemin grunt task

grunt-contrib-imagemin seems to be broken because several dependencies
are quite obsolete and cannot be downloaded.

rd_ui/Gruntfile.js

@@ -236,17 +236,6 @@ module.exports = function (grunt) {
     //   dist: {}
     // },
 
-    imagemin: {
-      dist: {
-        files: [{
-          expand: true,
-          cwd: '<%= yeoman.app %>/images',
-          src: '{,*/}*.{png,jpg,jpeg,gif}',
-          dest: '<%= yeoman.dist %>/images'
-        }]
-      }
-    },
-
     svgmin: {
       dist: {
         files: [{
@@ -348,7 +337,6 @@ module.exports = function (grunt) {
       ],
       dist: [
         'copy:styles',
-        'imagemin',
         'svgmin'
       ]
     },

rd_ui/package.json

@@ -12,7 +12,6 @@
     "grunt-contrib-copy": "^0.5.0",
     "grunt-contrib-cssmin": "^0.9.0",
     "grunt-contrib-htmlmin": "^0.3.0",
-    "grunt-contrib-imagemin": "^0.7.0",
     "grunt-contrib-jshint": "^0.10.0",
     "grunt-contrib-uglify": "^0.4.0",
     "grunt-contrib-watch": "^0.6.1",