initial start of dean's new homepage
the page
more updates
media files
img updates
correct images url
icon
font size larger
Merge remote-tracking branch 'origin/dev' into homepage-dean

Conflicts:
	templates/base.html
Unified Navbar
Added the new footer to all pages
Updated 'subtitle a video' page
New code for Team workflows

Added some code to make team workflows more extensible.  TeamWorkflows
implement SubitleWorkflows and also alter the pages in the team's
section like the dashboard and workflow settings page.

The plan from here is to:
  - Add extra TeamWorkflow subclasses to amara-enterprise.  This is
    what we will use for the collab-style teams
  - Add extra TeamWorkflow subclasses to our main repository.  I think
    we can create one for public teams, one for private teams, and
    maybe others.

Removed the is_moderated field from the team create form.  We weren't
using that value or displaying the widget to select it.
Wrong variable name (#1722)
Added workflow type to the TeamFactory (#1723)
Removed the Collaborators model

We are going to implement this with another app
Updated TeamFactory
Fixed a couple variable name issues (#1727, #1728)
Fixed constant name in TeamFactory
add workflow_type to team setup for tests.