Adds test for browserify

This commit adds tests to make sure that the browserify bundle will work in the dist file of clipboard.js

This commit adds the mocha and chai modules, since karma doesn't work well with node only tests.

Also splited tests tasks in package.json and updated .gitignore

package.json

@@ -6,9 +6,14 @@
   "main": "dist/clipboard.js",
   "browser": "src/clipboard.js",
   "browserify": {
-    "transform": [["babelify", {
-        "loose": "all"
-    }]]
+    "transform": [
+      [
+        "babelify",
+        {
+          "loose": "all"
+        }
+      ]
+    ]
   },
   "license": "MIT",
   "keywords": [
@@ -29,6 +34,7 @@
     "karma-mocha": "^0.2.0",
     "karma-phantomjs-launcher": "^0.2.1",
     "karma-sinon": "^1.0.4",
+    "mocha": "^2.3.3",
     "phantomjs-polyfill": "0.0.1",
     "uglify": "^0.1.5"
   },
@@ -36,6 +42,8 @@
     "publish": "npm run build && npm run minify",
     "build": "browserify src/clipboard.js -s Clipboard -o dist/clipboard.js",
     "minify": "uglify -s dist/clipboard.js -o dist/clipboard.min.js",
-    "test": "karma start --single-run"
+    "test": "npm run mocha | npm run karma",
+    "karma": "karma start --single-run",
+    "mocha": "mocha test/node.js"
   }
 }