Fixes for building docs
Added .travis.yml (for travis-ci) and tox.ini files

Targets:

* Runs the unit-tests for python 2.7
* Tests unit-test coverage
* Try to build docs
* Code style checks:
  * flake8
  * isort

Codes changes:
* Fixed tests for httpdownloader (using tmp dir)
* Implemented a couple of tests for Stats plugin but they fail to run on travis

Issues:
* Can't get py26 to work because of installing libtorrent through apt and
  the option system_site_packages fails for 2.6.
Disable plugins test due to Travis issue

An unknown issue with running the Stats plugins test on travis means it
never passes.
Small fixes for Travis and isort
[Docs] More fixes for testing with tox
Add isort thirdparty config for Travis
minor code cleanup
Fix isort config
Fix running docs build from setup
Update docs tests
Refactor/cleanup of tox.ini

 * Removed unused mock dep
 * Modified flake8 to run entire codebase (fixed exclude)
 * Change isort to shows files that need attention (no diff)
 * Uniform layout for tox.ini
 * Change flake8 complexity to 15
Fixes for flake8 and rtd
Switch from PIL to pillow for tox and rtd
Revert to isort diff output