Create a bot account for Coin production updates

We would like to have Coin bot account to be added in forward merge bots group with rights to create commits in Qt repositories. The push rights are required because we would need to push cherrypicks and merges for coin production updates from repositories located in coin master server (accessible only by CI admins) that will be made public by pushing the commits to qtqa/tqtc-coin-ci.git repository.

At the moment, coin admin needs to create the merge commit under their own account and resetting the commit author or alternatively by pulling the remote repository to their own local clone of qtqa/tqtc-coin-ci repository and then pushing the commit. This two-step process makes the process of pushing hotfixes and merges into production branches slow.

Adding a bot account for creating the commits would simplify this workflow by allowing all coin admins to create merges (currently only selective group have merge rights) and make it easier to distinguish bot-generated commits from regular commits.

Create coin-update-bot account into Gerrit. The purpose of the bot is to:

• update Coin source into the production from the gerrit
• push tags into Gerrit to mark which commit from the production branch is currently deployed