fix typo.
follow latest practis.
follow pyflakes.
use import style not to contain package name.
support py26
Merge branch 'feature/py26' into develop

* feature/py26:
  support py26
use pep8 and pyflakes while running setup.py test.
bump up version.
add py26 to travis.yml.
add module requirement for tests.
purge pyflakes.
pytest-flakes does not support python 3 yet. https://github.com/fschulze/pytest-flakes/pull/1
fix the version.
this update contains not only small fix but also new functionality, py26 support.
Merge branch 'develop'

* develop:
  fix the version. this update contains not only small fix but also new functionality, py26 support.
  purge pyflakes. pytest-flakes does not support python 3 yet. https://github.com/fschulze/pytest-flakes/pull/1
  add module requirement for tests.
  add py26 to travis.yml.
  bump up version.
  use pep8 and pyflakes while running setup.py test.
  support py26
  use import style not to contain package name.
  follow pyflakes.
  follow latest practis.
  fix typo.