chore(package): update firebase-functions-test to version 0.2.1

Closes #43

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
     "firebase-bolt": "^0.8.4",
     "firebase-tools": "^6.3.1",
     "jest": "^24.1.0",
-    "firebase-functions-test": "0.1.6",
+    "firebase-functions-test": "0.2.1",
     "chai": "^3.5.0",
     "chai-as-promised": "^6.0.0",
     "sinon": "^4.1.3"