[feature] add logging, use timedRotatingFileHandler

> user story: As a dev team member, I want the app to be setup with logs so that debugging issues would be easier

issues:
- https://github.com/wheresmybento/snakebite/issues/6

refs:
- http://victorlin.me/posts/2012/08/26/good-logging-practice-in-python
- https://docs.python.org/2/howto/logging-cookbook.html#logging-cookbook 

changes
- add logging handlers for app (via TimedRotatingFileHandler)
- set log configs in config files (only at 'dev.ini' for now)
- set datetime printing in app to follow [ISO 8601 format](http://en.wikipedia.org/wiki/ISO_8601)