add travis-ci configuration
fix travis script
add support for python 3
add support for python 2.6
Add cache and email support
bumpversion
add Env.email shortcut; update README.rst badges
Update README.rst
fix support for python 2.6 and 3
add Env.email shortcut test
fix coveralls badge
improved docs
add other yes-values
prettify NOTSET object
final fix badge