Fix tests, uses fork of http2 to support node 4.3.0 without ALPN

- the push server don't send TLS NPN and makes the http2 lib break
- the fork forces the next protocol negociation to h2 as we're sure

package.json

@@ -28,7 +28,7 @@
     "deepcopy": "^0.6.1",
     "express": "^4.13.4",
     "gcloud": "^0.28.0",
-    "http2": "^3.3.2",
+    "http2": "flovilmart/node-http2",
     "mailgun-js": "^0.7.7",
     "mime": "^1.3.4",
     "mongodb": "~2.1.0",