chore(package): update apollo-server-express to version 2.4.8

Closes #64

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "graphql-tools": "^1.2.1 || ^2.5.1"
   },
   "devDependencies": {
-    "apollo-server-express": "^1.1.2",
+    "apollo-server-express": "^2.4.8",
     "babel-cli": "^6.24.1",
     "babel-eslint": "^8.0.1",
     "babel-jest": "^21.2.0",