Removed redundancy

[meyer1994]

self.token is a property. It has a setter that just calls self._populate_attributes.

[coveralls]

Coverage decreased (-0.04%) to 90.457% when pulling d7776d2 on meyer1994:patch-1 into 800976f on requests:master.

[coveralls]

Coverage decreased (-0.04%) to 90.457% when pulling d7776d2 on meyer1994:patch-1 into 800976f on requests:master.

[coveralls]

Coverage decreased (-0.04%) to 90.457% when pulling d7776d2 on meyer1994:patch-1 into 800976f on requests:master.

[singingwolfboy]

This duplication is actually intentional: see #310 for more details.

Subclasses may override this token property to behave differently, while still expecting the base class to populate its internal attributes. This how Flask-Dance works -- calling the token setter activates the token storage backend.

Would it help to add a comment to that code instead, to make it clearer that this duplication is intentional?