message: Fix case of `gulp` argument in CONTRIBUTING.md
diff: @@ -94,7 +94,7 @@ This is my hack to simulate a click event based API in an IDE that doesn't have
  To push a release:
  ```bash
  -gulp release --semver [SEMVER] --githubToken [TOKEN]
  +gulp release --semver [SEMVER] --gitHubToken [TOKEN]
  git push --follow-tags
  ```
  