Integrate tox for testing

Adds:
* Moves all test commands into Tox
* Now specify testing dependent python packages in requirements-dev.txt
* Now build tests against py26 and py27 environments
Bump version and use standard MAJOR.MINOR.BUGFIX format
Add blank requirements.txt
Merge pull request #8 from striglia/proper_packaging

striglia: Proper packaging with tox
make fork() return self [cr by striglia]
allow any version of python with tox (don't depend on people having both 2.6 and 2.7 installed)
Merge pull request #9 from gatoatigrado/gatoatigrado-tox-any-python

allow any version of python with tox (don't depend on people having both 2.6 and 2.7 installed)
Add flake8 linting, make stylistic adjustments so it passes
Close queues from the main process, with some special flakiness-avoiding logic, because multiprocessing.queues is special :(
Add Travis CI config file (first attempt)
Add workaround to Travis bug mentioned at [ https://github.com/travis-ci/travis-cookbooks/issues/155 ]
Add Travis CI button to readme
Merge branch 'master' into gatoatigrado-close-queues
Changes from code review, thanks! Also, fix lint issues.
Tracked down leaked FDs (multiprocessing.Process pipes) and made it so everything is closed correctly.
Merge pull request #10 from gatoatigrado/gatoatigrado-close-queues

Close queues from the main process, with some special flakiness-avoiding...