feat(config): allow CoffeeScript configuration files

Require CoffeeScript in the cli file to enable CS configuration and spec
files.

Possibly fixes #38

Author: eddiemonge

lib/cli.js

@@ -5,6 +5,10 @@
  * Values from command line options override values from the config.
  */
 
+// Coffee is required here to enable config files written in coffee-script.
+// It's not directly used in this file.
+require('coffee-script');
+
 var util = require('util');
 var path = require('path')
 var fs = require('fs');

package.json

@@ -17,7 +17,8 @@
     "saucelabs": "~0.1.0",
     "glob": ">=3.1.14",
     "adm-zip": ">=0.4.2",
-    "optimist": "~0.6.0"
+    "optimist": "~0.6.0",
+    "coffee-script": "~1.6.3"
   },
   "devDependencies": {
     "expect.js": "~0.2.0",