Added default Vagrant gateway to INTERNAL_IPS

Makes Django Debug Toolbar show up too when running inside the Vagrant VM.
Replaced `yourapp` with `repo_name` template var.

No need to ask the user to replace it by hand, cookiecutter can do it for them.
Merge pull request #155 from martinblech/vagrant-gateway

Added default Vagrant gateway to INTERNAL_IPS
Add @martinblech to contributors
Added ATOMIC_REQUESTS=True to default DB setup

Quoting Two Scoops of Django:
> Use `ATOMIC_REQUESTS` as long as the performance overhead is bearable. That
> means "forever" on most sites.
Fix spelling mistakes in production config
Fix quote marks
Merge pull request #159 from chrisfranklin/patch-3

Few minor cleanups
Fix quote marks in common config to be consistent.
fix travis badget on README.rst
Merge pull request #163 from chrisfranklin/patch-3

Fix quote marks in common config to be consistent.
update requirements
Merge pull request #165 from luzfcb/update-requirements

update requirements
Tiny whitespace fix to force travis to fire
Merge pull request #157 from martinblech/replace-yourapp

Replaced `yourapp` with `repo_name` template var.
Merge pull request #158 from martinblech/atomic-requests

Added ATOMIC_REQUESTS=True to default DB setup
Added django-extensions to local configuration

It's one of the recommended apps in Two Scoops of Django. `runserver_plus` and
`shell_plus` are real time-savers!