fix(package): update spdy v3.4.1...4.0.0 (assertion error) (webpack#1491)

Author: odinho

package-lock.json

@@ -48,7 +48,7 @@
     "serve-index": "^1.7.2",
     "sockjs": "0.3.19",
     "sockjs-client": "1.3.0",
-    "spdy": "^3.4.1",
+    "spdy": "^4.0.0",
     "strip-ansi": "^3.0.0",
     "supports-color": "^5.1.0",
     "webpack-dev-middleware": "3.4.0",