Add pytest.ini

So far this just tells py.test not to recurse into directories
containing tests it doesn't need to run.
Update many unit tests to reflect 2yrs of changes

These tests hadn't been updated in over two years. Only one is left
failing.
Update test_connect() to reflect API changes

Looks like paramiko changed a bit internally. All unit tests pass now!
Merge pull request #102 from ceph/wip-tests

Update all existing unit tests.