Usemin/file-rev fix

[jaredpalmer]

Based on this yeoman/generator-angular#684 issue, in order for image references to work now, I think you need to change usemin settings in the Gruntfile:

From this:

usemin: {
  options: {
    assetsDirs: '<%= yeoman.dist %>'
  },

to this:

usemin: {
  options: {
    assetsDirs: ['<%= yeoman.dist %>','<%= yeoman.dist %>/img']
  },