change npm test to global karma for windows

README.md

@@ -135,6 +135,7 @@ Unit Tests can be run with [Karma][karmaUrl] and written using [Mocha][mochaUrl]
 
 ```console
 > npm install
+> npm install -g karma-cli
 > npm test
 ```
 

package.json

@@ -23,7 +23,7 @@
     "doc": "doc"
   },
   "scripts": {
-    "test": "./node_modules/karma/bin/karma start"
+    "test": "karma start"
   },
   "author": "",
   "license": "ISC"