Refactor.

Change-Id: I3785a0b943576e8a4e59f8438d60411ee301e1e2
Refactor.

Change-Id: I03467f0223e9afbdb72f6983f1764c763b5b1769
Refactor.

Change-Id: If32f747f2a2c7d8f039853455ee70a3c6fe6543a
Add tests.

Change-Id: Iad06655f46e05475dad9379a71ba547616712b12
Remove probably dead code.

This code looks dead because expiration_date is blank=False, null=False.

If this code is needed there should be test to it.

Change-Id: I5478ad9b3c0609924c0722bace9a60f07b3a96d8
Test parse_facebook_response and make it more robust.

Change-Id: I4e61a3da0dcae80c1d226ba0ca44c954040e2a72
Merge pull request #10 from tomwys/refactor

Refactor.