setup.py: Correct dependencies (fixes #21)
setup.py: Correct dependencies (fixes #21)

* Move imports to the last minute in setup.py.

* Declare pytz and dateutil as setup dependencies, as the setup process will
  import __init__.py, which in turn imports those two libraries.  In a pip
  or setuptools based install, this will fail.

j5int/python-datetime-tz,j5int/python-datetime-tz,mithro/python-datetime-tz,matthewhampton/python-datetime-tz,mithro/python-datetime-tz