test_oauth.py fails to import oauth2 unless oauth2 is already installed #61

Running the tests without installing oauth2 fails, this appears to be a simple case of not updating the library path before doing the import. The error is below.

python-oauth2/tests$ python test_oauth.py
Traceback (most recent call last):
File "test_oauth.py", line 29, in
import oauth2 as oauth
ImportError: No module named oauth2