Merge pull request #116 from mdevaev/req-objgraph

Added objgraph to requirements.txt
Using tox for testing; minimalistic pylint.ini
tox fixes
README.md: Removed travis from bottom
Temporary removed flake8 from tox
Merge pull request #119 from mdevaev/tox

Using tox for travis and local testing
Added some debugs for ShotServer
Added debugs to do_POST()
Added flow markers to tests/test_flow.py
README.md: info about submodules