Disable automated merge of PR after successful PR build to enable more robust code reviews

[bfitzpat]

We encountered a small hiccup when dealing with camel-tooling/generator-camel-project#38. As soon as the PR was marked "ok to test" and built successfully without errors, another automated process swooped in and merged the PR though a second review pass was in flight and two additional comments were noted for possible fixes to the code introduced.

Instead of an automated process, we might recommend making the merge a manual one? Or at the very least bumping up the time between a successful PR build and the automated merge (perhaps 24 hours?).