title: Grunt "watch.sass.files" missing
body: <p>Beginning with Grunt, which I love but cannot make it work as I get continously an error with my sass implementation. I get the following alerts:</p>
  
  <pre><code>Danis-MacBook-Pro:020 DanielRamirez$ grunt
  Running "concat:dist" (concat) task
  File "js/build/production.js" created.
  
  Running "uglify:build" (uglify) task
  File js/build/production.min.js created.
  &gt;&gt; No "sass" targets found.
  Warning: Task "sass" failed. Use --force to continue.
  
  Aborted due to warnings.
  Danis-MacBook-Pro:020 DanielRamirez$ 
  </code></pre>
  
  <p>If I <code>--force</code> I get the following:</p>
  
  <pre><code>Danis-MacBook-Pro:020 DanielRamirez$ grunt
  Running "concat:dist" (concat) task
  File "js/build/production.js" created.
  
  Running "uglify:build" (uglify) task
  File js/build/production.min.js created.
  &gt;&gt; No "sass" targets found.
  Warning: Task "sass" failed. Use --force to continue.
  
  Aborted due to warnings.
  Danis-MacBook-Pro:020 DanielRamirez$ 
  </code></pre>
  
  <p>This is my Gruntfile.js:</p>
  
  <pre><code>module.exports = function(grunt) {
  
      // 1. All configuration goes here
      grunt.initConfig({
  
          pkg: grunt.file.readJSON('package.json'),
  
          // 2. Configuration for concatinating files goes here.
  
          // Concatonate various files into one
          concat: {
              dist: {
                  src: [
                      'js/vendor/*.js', // All JS in the libs folder
                      'js/plugin.js', // All JS in the libs folder
                      'js/global.js'  // This specific file
                  ],
                  dest: 'js/build/production.js',
              }
          },
  
          // Creates a minified version of the javascript files of the project
          uglify: {
              build: {
                  src: ['js/vendor/*.js', 'js/plugin.js', 'js/global.js'],
                  dest: 'js/build/production.min.js'
              }
          },
  
           // Minifies automatically the images of the project
          // imagemin: {
          //     dynamic: {
          //         files: [{
          //             expand: true,
          //             cwd: 'images/',
          //             src: ['**/*.{png,jpg,gif}'],
          //             dest: 'images/build/'
          //         }]
          //     }
          // },
  
          // Watches for changes done on the project and builds the commands if neccesary
          watch: {
  
               options: {
                  livereload: true,
              },
  
              scripts: {
                  files: ['js/*.js'],
                  tasks: ['concat', 'uglify'],
                  options: {
                      spawn: false,
                  },
              },
  
              sass: {
                  dist: {
                      options: {
                          style: 'compressed'
                      },
                      files: {
                          'css/build/style.css': 'sass/style.scss'
                      }
                  }
              },
  
              css: {
                  files: ['css/*.scss'],
                  tasks: ['sass'],
                  options: {
                      spawn: false,
                  }
              }
          }
  
      });
  
      // 3. Where we tell Grunt we plan to use this plug-in.
      grunt.loadNpmTasks('grunt-contrib-concat');
      grunt.loadNpmTasks('grunt-contrib-uglify');
      // grunt.loadNpmTasks('grunt-contrib-imagemin');
      grunt.loadNpmTasks('grunt-contrib-sass');
      grunt.loadNpmTasks('grunt-contrib-compass');
      grunt.loadNpmTasks('grunt-contrib-watch');
  
      // 4. Where we tell Grunt what to do when we type "grunt" into the terminal.
      grunt.registerTask('default', ['concat', 'uglify', 'sass', 'compass', 'watch']);
  
  };
  </code></pre>
  
  <p>Any ideas?</p>