.encode in __repr__ incorrect

[bronger]

I think the encode method calls in the __repr__ methods on sickle/models.py is incorrect. FWIW, I get exceptions with those:

>>> list(sickle.ListSets())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/dist-packages/sickle/models.py", line 168, in __repr__
    return u'<Set %s>'.encode('utf8') % self.setName
TypeError: %b requires a bytes-like object, or an object that implements __bytes__, not 'str'

If I delete them, everything looks fine.

[mloesch]

Fixed in release 0.6.5