RepoCommandTest: Don't wrap create{Bare,Work}Directory in t-w-r

RepoCommandTest: Don't wrap create{Bare,Work}Directory in t-w-r

These methods add the created Repository into "toClose", and they are
then closed by LocalDiskRepositoryTestCase's tearDown method.

Calling them in try-with-resource causes them to first be closed in
the test method, and then again in tearDown, which results in the use
count going negative and a log message on the console.

While this is not a serious problem, having so many false positives
in the logs will potentially drown out real cases of Repository being
closed too many times.

Change-Id: Ib374445e101dc11cb840957b8b19ee1caf777392
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>