Small bugfix in poll_agent
Merge pull request #149 from guidow/poll_agent_bugfixes

This is a very small and self-contained fix, so I'm merging it directly.
Remove unused module tasks.py

Task endpoints have since been implemented under jobs and agents
Merge pull request #151 from guidow/dead_code_removal

Remove unused module tasks.py
removing allowed failure for pymysql, sqlalchemy 0.9.3 has been out for a while
adding sqlalchemy>=0.9.3
Merge pull request #152 from pyfarm/pymysql_no_allowed_failure

Remove PyMySQL driver from allowed_failures