Update requests dependency to `>=2.0`
pushnotify depends on
requests==1.1.0, but latest version is
2.2.1 as of now.
This by itself doesn't cause any problems, but there are quite a lot other libraries that use
requests>=2.0 and since pip doesn't handle conflicts well this poses a problem.
Glancing over http://docs.python-requests.org/en/latest/api/#migrating-to-2-x it looks to me that update would only require updating
setup.py or at most very small amount of changes.