Add pagination methods.

The pagination methods will ease the pagination of
list of objects.
Add commit validation before deploying.

If heroku commits are pushed to ``heroku`` before
to ``origin/master`` the history could be out of sync,
giving problems with the commit history.
Add active profile manager.

The ``active`` manager for the ``Profile`` model
will filter any account unactivated or any user
administrator account from being listed in the
list of people.
Add people list section.

https://github.com/madewithbytes/us_ignite/issues/47

Logged in users will be able to see a list of registered
members.

The list has support for pagination.

Refers #47.