Add webkit test script

Author: MarcoPolo

package.json

@@ -95,6 +95,7 @@
     "test:chrome-webworker": "aegir test -t webworker -f \"./dist/test/**/*.spec.js\"",
     "test:firefox": "aegir test -t browser -f \"./dist/test/**/*.spec.js\" -- --browser firefox",
     "test:firefox-webworker": "aegir test -t webworker -f \"./dist/test/**/*.spec.js\" -- --browser firefox",
+    "test:webkit": "aegir test -t browser -f \"./dist/test/**/*.spec.js\" -- --browser webkit",
     "test:examples": "cd examples && npm run test:all",
     "test:interop": "aegir test -t node -f dist/test/interop.js"
   },