Import error when installing accli using setup.py
When using setup.py (or pip install) to get accli command installed, the following import error is shown:
```
Traceback (most recent call last):
File "/home/joseluis/repos/accli/venv/bin/accli", line 11, in <module>
load_entry_point('accli==0.0.1', 'console_scripts', 'accli')()
File "/home/joseluis/repos/accli/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 561, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/home/joseluis/repos/accli/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2631, in load_entry_point
return ep.load()
File "/home/joseluis/repos/accli/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2291, in load
return self.resolve()
File "/home/joseluis/repos/accli/venv/lib/python3.5/site-packages/pkg_resources/__init__.py", line 2297, in resolve
module = __import__(self.module_name, fromlist=['__name__'], level=0)
File "/home/joseluis/repos/accli/venv/lib/python3.5/site-packages/accli/cli.py", line 6, in <module>
from accli.commands import InitCmd, InvoiceCmd
ImportError: No module named 'accli.commands'
```
issue