old_contents: module.exports = function(grunt) {
    grunt.initConfig({
      bower: {
        install: {
          options: {
            copy: false
          }
        }
      },
  
      sass: {
        dist: {
          options: {
            style: 'compressed',
            includePaths: [ 'bower_components' ]
          },
          files: {
            'public/stylesheets/application.css' : 'public/stylesheets/application.scss'
          }
        }
      },
  
      watch: {
        sass: {
          files: [ 'public/stylesheets/**/*.scss' ],
          tasks: [ 'sass:dist' ]
        }
      }
    });
  
    grunt.registerTask('default', [ 'bower:install', 'sass:dist' ]);
    require("matchdep").filterDev("grunt-*").forEach(grunt.loadNpmTasks);
  }
  
new_contents: module.exports = function(grunt) {
    grunt.initConfig({
      bower: {
        install: {
          options: {
            copy: false
          }
        }
      },
  
      sass: {
        dist: {
          options: {
            style: 'compressed',
            includePaths: [ 'bower_components' ]
          },
          files: {
            'public/stylesheets/application.css' : 'public/stylesheets/application.scss'
          }
        }
      },
  
      watch: {
        sass: {
          files: [ 'public/stylesheets/**/*.scss' ],
          tasks: [ 'sass:dist' ]
        }
      }
    });
  
    grunt.registerTask('default', [ 'bower:install', 'sass:dist' ]);
  
    grunt.registerTask('heroku', ['default']);
  
    require("matchdep").filterDev("grunt-*").forEach(grunt.loadNpmTasks);
  }
  
subject: Add heroku task in Grunt