enforce casing / formatting rules for profiles

[owocki]

per convo in slack

[owocki]

testing

In [1]: from dashboard.models import Profile

In [2]: owocki = Profile.objects.get(handle='owocki')

In [3]: owocki.handle = '@OWOCKI '

In [4]: owocki.save()

In [5]: owocki = Profile.objects.get(handle='owocki')

In [6]: owocki.handl,e
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-6-2eff224d1db4> in <module>
----> 1 owocki.handl,e

AttributeError: 'Profile' object has no attribute 'handl'

In [7]: owocki.handle
Out[7]: 'owocki'

[mbeacom]

lgtm 🚢