Can't install py-elevator if PyZMQ isn't already installed

[k4nar]

I just got this error on Travis :

Downloading/unpacking git+git://github.com/onitu/py-elevator.git@onitu (from -r /home/travis/build/onitu/onitu/requirements.txt (line 2))

Cloning git://github.com/onitu/py-elevator.git (to onitu) to /tmp/pip-_snIZL-build

Running setup.py (path:/tmp/pip-_snIZL-build/setup.py) egg_info for package from git+git://github.com/onitu/py-elevator.git@onitu

Traceback (most recent call last):
File "<string>", line 17, in <module>
File "/tmp/pip-_snIZL-build/setup.py", line 9, in <module>
version = __import__('pyelevator').__version__
File "pyelevator/__init__.py", line 15, in <module>
from .client import Elevator
File "pyelevator/client.py", line 7, in <module>
from .base import Client
File "pyelevator/base.py", line 11, in <module>
import zmq
ImportError: No module named zmq
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "<string>", line 17, in <module>
File "/tmp/pip-_snIZL-build/setup.py", line 9, in <module>
version = __import__('pyelevator').__version__
File "pyelevator/__init__.py", line 15, in <module>
from .client import Elevator
File "pyelevator/client.py", line 7, in <module>
from .base import Client
File "pyelevator/base.py", line 11, in <module>
import zmq
ImportError: No module named zmq

We should not use an import to get the current version.