`git-annex test` prevents ~/.gitconfig or /etc/gitconfig from being read.
The `-c` option also doesn't propagate into the test suite. 

It would sometimes be useful to test git-annex with a given git config set.
Although some might break the test suite, others might expose actual bugs
in git-annex. --[[Joey]]

> Added "--test-git-config" option, [[done]] --[[Joey]]