old_contents: module.exports = function (grunt) {
  
  	grunt.initConfig({
  
  		meta: {
  			banner: '// ' + grunt.file.read('LICENSE').split("\n")[0]
  		},
  
  		concat: {
  			dist: {
  				src: ['<banner>', 'lib/observable.js'],
  				dest: 'lib/observable.js'
  			}
  		},
  
  		coffee: {
  			compile: {
  				files: {
  					'lib/observable.js': 'lib/observable.coffee'
  				}
  			}
  		}
  
  	});
  
  	grunt.loadNpmTasks('grunt-contrib-coffee');
  
  };
new_contents: module.exports = function (grunt) {
  
  	grunt.initConfig({
  
  		meta: {
  			banner: '// ' + grunt.file.read('LICENSE').split("\n")[0]
  		},
  
  		concat: {
  			dist: {
  				src: ['<banner>', 'lib/observable.js'],
  				dest: 'lib/observable.js'
  			}
  		},
  
  		coffee: {
  			compile: {
  				files: {
  					'lib/observable.js': 'lib/observable.coffee'
  				}
  			}
  		},
  
  		mocha: {
  			all: {
  				src: 'spec/index.html',
  				run: true
  			}
  		}
  
  	});
  
  	grunt.loadNpmTasks('grunt-contrib-coffee');
  	grunt.loadNpmTasks('grunt-mocha');
  
  };
subject: add mocha task