fix(package): update express-graphql to version 0.9.0

Closes #99

Author: greenkeeper[bot]

package.json

@@ -30,7 +30,7 @@
     "cookie-parser": "1.4.3",
     "debug": "^4.1.0",
     "express": "^4.16.4",
-    "express-graphql": "^0.7.1",
+    "express-graphql": "^0.9.0",
     "graphql": "^14.0.0",
     "joi": "^14.0.0",
     "joi-date-extensions": "^1.2.0",