revert: "update graphql to version 0.12.0 (#2)" (#3)

This reverts commit d563caa.

Author: jlengstorf

package.json

@@ -52,7 +52,7 @@
     "eslint-config-prettier": "^2.3.0",
     "eslint-plugin-import": "^2.7.0",
     "eslint-plugin-prettier": "^2.1.2",
-    "graphql": "^0.12.0",
+    "graphql": "^0.11.7",
     "graphql-tools": "^2.5.1",
     "husky": "^0.14.3",
     "jest": "^21.2.1",