pytz is also required.

>>> from bulbs.neo4jserver import Graph
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/lew21/test/sem/lib/python3.3/site-packages/bulbs/neo4jserver/__init__.py", line 6, in <module>
    from bulbs.config import Config, DEBUG, INFO, WARNING, ERROR, CRITICAL
  File "/home/lew21/test/sem/lib/python3.3/site-packages/bulbs/config.py", line 7, in <module>
    from .utils import get_logger, urlparse
  File "/home/lew21/test/sem/lib/python3.3/site-packages/bulbs/utils.py", line 14, in <module>
    import pytz
ImportError: No module named 'pytz'