Deprecation of some of the GitHub events

[chshersh]

From the mail:

We no longer support two events which your GitHub Apps may rely on, "integration_installation" and "integration_installation_repositories".

These events can be replaced with the "installation" and "installation_repositories" events respectively.

The "integration_installation" and "integration_installation_repositories" events will be removed after October 1st, 2020.

Please visit https://developer.github.com/changes/2020-04-15-replacing-the-installation-and-installation-repositories-events for more information about suggested changes, brownouts, and removal dates.