Add Action to DeploymentStatusEvent

[JoannaaKL]

In GH docs we can see that deployment_status has a field action, that is always set to created. This pr adds it to json representation.

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 92.89%. Comparing base (2b8c7fa) to head (88abac8).
Report is 52 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3163 +/- ##
==========================================
- Coverage 97.72% 92.89% -4.83% 
==========================================
Files 153 171 +18 Lines 13390 11476 -1914 ==========================================
- Hits 13085 10661 -2424 - Misses 215 724 +509 - Partials 90 91 +1 

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[gmlewis]

Thank you, @JoannaaKL !
LGTM.
Merging.