Fix bug on using requests 1.0.4

Method requests.session() has no arguments on requests 1.0.4. They have removed them on commit https://github.com/kennethreitz/requests/commit/6acce57271efce8c17cea2f1eece943f429e3879#requests/sessions.py
Merge pull request #54 from mativs/master

requests.session method don't accept parameters and API creation fails