Validate git reference when Deployment Process is saved

[iryan2]

The enhancement

The Need

When creating a release and the git repo has issues (invalid repo, invalid credentials) it shows this error

When saving the step in the deployment process though, it was all valid.

Solution

Validate the referenced git repository when the user saves their Deployment Process, instead of when they're creating a Release.

Screenshots and Mockups

Existing experience - issue with git reference doesn't get raised until the user attempts to create a release:

Desired - git reference validation error is raised when the user attempts to save their deployment process:

[iryan2]

Release notes: Git credentials will now be validated when saving a Deployment Process (previously this check only happened when creating a Release)