Fix "go install -v . ./.git/logs/refs/heads ./.git/refs/heads ..."

This happens when you name a git object (branch, tag, etc) `something_test.go`.

Signed-off-by: Andrew Page <admwiggin@gmail.com>
Merge pull request #213 from tianon/crosbymichael_test.go

Fix "go install -v . ./.git/logs/refs/heads ./.git/refs/heads ..."