Adds support for get_bodyweight and get_bodyfat.

Hey there, 

This fixes #25, by adding `get_bodyweight` and `get_bodyfat` methods.

Both have test coverage, and I've aimed to match the existing style.  Tested, and working, here:

```python
client.get_bodyweight()
>>> {u'weight': [{u'date': u'2014-03-29', u'logId': 1396089789000, u'bmi': 22.38, u'weight': 165, u'time': u'10:43:09'}, {u'date': u'2014-03-29', u'logId': 1396097620000, u'bmi': 22.41, u'weight': 165.3, u'time': u'12:53:40'}]}
client.get_bodyfat()
>>> {u'fat': [{u'date': u'2014-03-29', u'logId': 1396089789000, u'fat': 16.9, u'time': u'10:43:09'}, {u'date': u'2014-03-29', u'logId': 1396097620000, u'fat': 16.9, u'time': u'12:53:40'}]}
```

Threw in a version bump and tossed myself on AUTHORS since that's what I ask most people to do when they add PRs to my libs.

Cheers!
-Steven