fix(build): Fix npm test and test:watch commands for windows

Single quotes and semicolons don't work as expected on windows.

Closes angular#217

Author: fabien0102

package.json

@@ -5,11 +5,11 @@
   "main": "bundles/angularfire2.umd.js",
   "module": "index.js",
   "scripts": {
-    "test": "npm run build; karma start --single-run",
-    "test:watch": "concurrently 'npm run build:watch' 'npm run delayed_karma'",
+    "test": "npm run build && karma start --single-run",
+    "test:watch": "concurrently \"npm run build:watch\" \"npm run delayed_karma\"",
     "delayed_karma": "sleep 10 && karma start",
     "delayed_rollup": "sleep 5 && rollup --watch -c rollup.test.config.js",
-    "build:watch": "rm -rf dist && concurrently 'tsc -w' 'npm run delayed_rollup'",
+    "build:watch": "rm -rf dist && concurrently \"tsc -w\" \"npm run delayed_rollup\"",
     "build": "rm -rf dist && tsc && rollup -c rollup.test.config.js",
     "build_npm": "rm -rf dist && ngc -p tsconfig.publish.es6.json && rollup -c rollup.publish.config.js && npm run postbuild_npm",
     "build_e2e": "rm -rf dist-test && npm run build && tsc -p test/ && cp test/e2e/firebase_object/index.html dist-test/e2e/firebase_object/ && cp test/e2e/firebase_list/index.html dist-test/e2e/firebase_list/ && cp test/e2e/auth/index.html dist-test/e2e/auth/",