Add Changes field to RepositoryEvent

[gmlewis]

Fixes: #2232 .

[gmlewis]

@ecrupper - please take a look and let me know what you think.

[codecov]

Codecov Report

Merging #2233 (0f786cc) into master (fef3638) will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #2233 +/- ##
=======================================
Coverage 97.81% 97.81% =======================================
Files 112 112 Lines 10117 10117 =======================================
Hits 9896 9896 Misses 154 154 Partials 67 67 

Impacted Files	Coverage Δ
github/event_types.go	100.00% <ø> (ø)

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[ecrupper]

Pulled this down locally and applied it to my repo rename webhook logic and it worked like a charm! Thanks so much for this!

[gmlewis]

Thank you, @ecrupper !

Awaiting second LGTM before merging.
Note that any other repo contributor can review and approve this PR. Thanks!

[gmlewis]

Thank you, @pierce-m !
Merging.