Add requirements.txt

This fix issue with online documentation and
ReadTheDocs.org is able to generate documentation for the project
Bump version: 0.2.24 → 0.2.25
closes issues #79
Bump version: 0.2.25 → 0.2.26
Fixes: updated document format to make it similar to devel branch.
fix pep8
Fix #80, added 'requirements.txt'
Bump version: 0.2.26 → 0.2.27
Merge branch 'master' into devel

Conflicts:
	.bumpversion.cfg
	raxas/auth.py
	raxas/version.py