chore(package): update @types/graphql to version 0.12.1

Closes #12

Author: greenkeeper[bot]

package.json

@@ -34,7 +34,7 @@
     "minimatch": "^3.0.4"
   },
   "devDependencies": {
-    "@types/graphql": "^0.11.0",
+    "@types/graphql": "^0.12.1",
     "@types/lodash": "^4.14.80",
     "@types/minimatch": "^3.0.1",
     "ava": "^0.23.0",