Beachball does not retry post git failure

[Vidit Mathur]

Currently post bumping the package to feed when beachball does a git fetch, it does not account for a failure in the git fetch task, and in case it fails(for example: due to network issue), beachball does not retry the task.
This results in the packages being published but versions not appropriately bumped and merged back.

The resolution could be to catch the task failures and retry the particular task.