TODO
test helper: Assertions.assertContainsInOrder

also used in show command
Repo.ATTRIBUTES has order
moved logic behind command show to Repo.print_attributes

also eliminated default attribute values for get_as_pip_conf:
get_as_pip_conf is raising an error on missing attributes
Repo.print_attributes
Badly configured repos are instantiated as NullRepo
NullRepo -> BadRepo
Repos have a name
BadRepo - improve outputs
colored output for show
Repo.print_attributes: slight function depth reduction & junk attributes are sorted
TODO
Merge branch 'feature/command-show-attribute-ordering' into develop