⬆️ Bump graphql-tools from 4.0.8 to 6.2.1

Bumps [graphql-tools](https://github.com/ardatan/graphql-tools) from 4.0.8 to 6.2.1.
- [Release notes](https://github.com/ardatan/graphql-tools/releases)
- [Commits](ardatan/graphql-tools@v4.0.8...v6.2.1)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -45,7 +45,7 @@
     "eslint-plugin-promise": "^4.0.1",
     "eslint-plugin-standard": "^4.0.0",
     "graphql": "^14.0.2",
-    "graphql-tools": "^4.0.3",
+    "graphql-tools": "^6.2.1",
     "mocha": "^5.2.0",
     "nyc": "^13.1.0",
     "validator": "^10.9.0"