added pyup.io (replaces requires.io)
added pyup.io (replaces requires.io)

- way faster than the old service
- PRs are created by pyupbot and not the last person who logged in to the web service
- PR description contains changelog of dependency
- pyupbot is open source
- web interface is pretty and simple

closes #153

d120/pyophase,d120/pyophase,d120/pyophase,d120/pyophase