Make repository excludes more dynamic

[bastelfreak]

At the moment we've some hardcoded globbing in our repository model:

vox-pupuli-tasks/app/models/repository.rb

Lines 22 to 24 in 129a0ee

	def self.notably?(name)
	/^puppet-(?!lint)/.match?(name) && LEGACY_OR_BROKEN_NOBODY_KNOWS.exclude?(name)
	end

We need to refactor this and save the complete excludes in our yaml. Afterwards we can enable it for more repositories, for example our gems (or everything that's not archived).

@ekohl after this is implemented, the app can also manage labels for your voxpupuli-test and voxpupuli-acceptance repositories.

[Flipez]

Related to #304