Adding Travis-CI configuration file.
Add the travis-ci green/red badge to the readme file.
Adding Gregor Müllegger to the CONTRIBUTORS file.
merge
Merge pull request #49 from gregmuellegger/travis-ci

Implementing Travis CI integration.
merge
Refactor views to use new Admin2Mixin
Fixing setup.py if django is not installed.

djadmin2 must not be imported in setup.py because this triggers an import of
django and other dependencies which will obviously fail if they are not
installed.
Fix incorrect template being extended.
Merge branch 'issue44' of git://github.com/inglesp/django-admin2 into inglesp-issue44
Merge pull request #52 from audreyr/template-fixes

Fix incorrect templates being extended.
Merge pull request #53 from gregmuellegger/setuppy-fix

Fixing setup.py if django is not installed.