Fix some typos
Fix pip==1.3.1 'default_vcs' bug

Pip==1.3.1 parse_requirements helper requires an options object, so
parsing requirements with it raises a NoneType error has no
'default_vcs' attribute.

Fixing the issue and adding testing support for pip==1.3.1 in tox and
Travis-ci.
Merge branch 'bug/pip131_default_vcs_error'
New pypi release (0.0.1a4)

Fixing news, so it´s also included in the pypi page.