Move test_os_server and apply fixes.

- Add missing meta value for test_create_server
- Add .gitignore for pytest .cache directory

Exclude test_os_server from nose test runs since it was designed
for pytest. The test will work correctly when run using pytest.

This is a temporary issue, as we'll be moving to pytest soon.

.gitignore

@@ -54,6 +54,7 @@ credentials.yml
 *.out
 .coverage
 .tox
+.cache
 results.xml
 coverage.xml
 /test/units/cover-html