Update testing settings

While testing I found those test arguments useful and decided to make them accessible for future developers.

`NOSE_ARGS` contains option flag to run doctests with options `ELLIPSIS`. This is relevant if others will want to run or write new doctests. The `--nocapture` is for not capturing stdout -- useful when debugging. 
Running nosetest with doctests enabled causes a traceback:

```
======================================================================
ERROR: Failure: AlreadyRegistered (The model SysterUser is already registered)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/nose/loader.py", line 414, in loadTestsFromName
    addr.filename, addr.module)
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/nose/importer.py", line 47, in importFromPath
    return self.importFromDir(dir_path, fqname)
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/nose/importer.py", line 94, in importFromDir
    mod = load_module(part_fqname, fh, filename, desc)
  File "/home/ana/workspace/portal/systers_portal/systers_portal/urls.py", line 5, in <module>
    admin.autodiscover()
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/django/contrib/admin/__init__.py", line 29, in autodiscover
    import_module('%s.admin' % app)
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/django/utils/importlib.py", line 40, in import_module
    __import__(name)
  File "/home/ana/workspace/portal/systers_portal/dashboard/admin.py", line 6, in <module>
    admin.site.register(SysterUser)
  File "/home/ana/workspace/portal/venv/local/lib/python2.7/site-packages/django/contrib/admin/sites.py", line 77, in register
    raise AlreadyRegistered('The model %s is already registered' % model.__name__)
AlreadyRegistered: The model SysterUser is already registered
```

So it fails on `admin.autodiscover()`. When running without doctests, the `urls.py` is not being imported and hence the models are not registered twice. 

By the way when running tests on a specific app, it doesn't fail - `python systers_portal/manage.py test --settings=systers_portal.settings.testing systers_portal.dashboard`

The only workaround that I could find is to wrap the `admin.autodiscover()` in a try/except block.
```python
try:
    admin.autodiscover()
except admin.sites.AlreadyRegistered:
    pass
```