title: Grunt Uglify wildcard and versioning
body: <p>I've been trying for some time now to combine two Grunt JS plugins in a particular way. 
  Basically, I want to minify all JS files in a directory using UglifyJS. Following this, I would like to use a versioning plugin (in this case grunt-static-versioning) to achieve cache busting.</p>
  
  <p>My gruntfile is as follows:</p>
  
  <pre><code>module.exports = function(grunt) {
  grunt.initConfig({
    clean: ['dest/js'],
    uglify: {
      options: {
        report: 'min',
        mangle: true
      },
      my_target: {
        files: [{
        expand: true,
        cwd: 'src/js',
        src: '**/*.js',
        dest: 'dest/js'
        }]
      }
    },
    cssmin: {
      options: {
      report:'min'
      },
      minify: {
          expand:true,
      cwd: 'src/css',
      src: '**/*.css',
      dest: 'dest/css',
      }
    },
    imagemin: {
      dynamic: {
        options: {
          optimizationLevel: 7
        },
        files: [{
          expand:true,
          cwd: 'src/assets',
          src: ['**/*.{png,jpg,gif}'],
          dest: 'dest/assets'
        }]
      }
    },
    htmlmin: {
      mini :{
        options: {
          removeComments: true,
          collapseWhitespace: true,
          collapseBooleanAttributes: true,
          removeAttributeQuotes: true,
          removeRedundantAttributes: true,
          removeEmptyAttributes: true,
          useShortDoctype: true
        },
        files: [{
          expand:true,
          cwd: 'src',
          src: '**/*.html',
          dest: 'dest'
        }]
      }
    },
    versioning: {               // Task
      options: {                // Task options
        cwd: ''
      },
      dist: {                   // Target
        options: {              // Target options
        },
        files: [{
          assets: '&lt;%= uglify.my_target.files %&gt;', 
          key: 'global',
          dest: 'dest/js',
          type: 'js',
          ext: '.js'
        }]
      }
    }
  });
  grunt.loadNpmTasks('grunt-contrib-clean');
  grunt.loadNpmTasks('grunt-static-versioning');
  grunt.loadNpmTasks('grunt-contrib-uglify');
  grunt.loadNpmTasks('grunt-contrib-cssmin');
  grunt.loadNpmTasks('grunt-contrib-imagemin');
  grunt.loadNpmTasks('grunt-contrib-htmlmin');
  
  
  grunt.registerTask('default', ['clean', 'uglify', 'cssmin', 'imagemin', 'htmlmin', 'versioning']);}
  </code></pre>
  
  <p>However, upon execution I get the following error:</p>
  
  <pre><code>Running "versioning:dist" (versioning) task
  Warning: Unable to read "dest/js" file (Error code: EISDIR). Use --force to continue.
  </code></pre>
  
  <p>I understand this error occurs because dest/js is not a file but a directory, but I don't know how to tell version the correct file names. Is there a particular Grunt JS format to do this?</p>