add github app details into digital ocean

[Felipe-gsilva]

;; config edn example:

 :git-sync {:secret #or [#env GITHUB_APP_SECRET ""]
            :app-id #or [#env GITHUB_APP_ID ""]
            :api-url #or [#env GITHUB_API_URL ""]
            :private-key #or [#env GITHUB_PRIVATE_KEY ""]}

we need this data inside digital ocean envvar for handling git operations