npm test line simpler, works from cmd as well as sh

package.json

@@ -25,7 +25,7 @@
         "ambers": "./bin/server"
     },
     "scripts": {
-        "test": "sh -c 'grunt amberc:amber_test_runner' && node ./test/amber_test_runner.js"
+        "test": "grunt amberc:amber_test_runner && node ./test/amber_test_runner.js"
     },
     "devDependencies": {
         "pegjs": "~0.7.0",