Update firebase-functions peer dependency (#10)

Author: laurenzlong

package.json

@@ -37,15 +37,15 @@
     "@types/chai": "^4.1.2",
     "@types/mocha": "^5.0.0",
     "chai": "^4.1.2",
-    "firebase-functions": "^1.0.1",
+    "firebase-functions": ">1.0.1",
     "firebase-admin": "^5.12.0",
     "mocha": "^5.0.5",
     "sinon": "^4.4.9",
     "tslint": "^5.8.0",
     "typescript": "^2.4.1"
   },
   "peerDependencies": {
-    "firebase-functions": "^1.0.1",
+    "firebase-functions": ">1.0.1",
     "firebase-admin": "^5.12.0"
   },
   "engines": {