Add ``Application`` model ``is_editable_by`` logic.

The model validates if the given ``User`` can edit
the given application.

The comparison relies on a ``hash`` of the user instance
so it should have be a saved instance.
List visible ``Applications``in the user ``Profile``.

https://github.com/madewithbytes/us_ignite/issues/67

The owned applications are listed in the User ``Profile``
accordingly to the user that is logged in.

If the owner is viewing its own profile all the
applications are listed, otherwise only the ``PUBLISHED``
applications.

A function has been aded to determine the logic.

Closes #67.
Add ``is_draft`` method to the ``Application``.

This method will help to determine if an application
is a ``DRAFT`` and display or hide items accordingly.
Change the ``Application`` add form to be an include.

By having the form as an include template is easier
to reuse it in other context, e.g.: Edit Applicaton.
Add link to the profile from the navigation bar.
List ``DRAFT`` status in the title of an ``Application``

This makes it more prominent.
Add ``success`` message confirmation for new ``Applications``

After an application has been created a flash
message will aknowledge the status.
Removed unused ``AuthenticationMiddleware``.

The middleware would provide a basic www-challenge
in order to access the app.
Add ``TestMessagesBackend`` for testing ``django.contrib.messages``.

When unit testing a django view the ``messages`` middleware
will be missing. This backend will provision a simple
messaging midleware.

Usage::

    from django.test import client
    from us_ignite.common.tests import utils

    factory = client.RequestFactory()
    request = factory.get('/')
    request._messages = utils.TestMessagesBackend(request)

The messages will be added to this simple backend.
Add edit ``Application`` functionality.

https://github.com/madewithbytes/us_ignite/issues/68

The aplication can only be edited by the ``owner``
of the application.

The edit link can be found in the page detail of
the application.

Closes #68.