Submodules with non-default base branch name

[pwalczysko]

Replacing the ome/governance#4

Problem

The scc is by default only taking into account PRs open against the base branch of a submodule. This is working fine for minutes and schemas (both have base branch named master) but the governace submodule base branch name does not comply with the scc expectation as the governance's base branch name is main.

How does it demonstrate

The PRs such as ome/governance#3 were ignored by the Jenkins WEBSITE-push job.

[pwalczysko]

Potentially solved by #882 - addition of the repository.yml file where the base branch of governance is specified as main is enough for scc to include PRs such as ome/governance#3

cc @sbesson @joshmoore