Initial commit of new UI. There is still some work to be done before this goes into dev, but here is the work so far:
* Updated dependencies to latest 2.x django
* Updated to Bootstrap 4
* New home screen to display most recent satellite entries, most recent data, and contributors
* Adopted django-bootstrap-modal-forms for handling satellite and transmitter creation and update, with more of an emphasis on django's model/view/form model - and a dynamic flow where the modals and details are only loaded when the proper icon is clicked, reducing the overall page size
* Adopted AdminLTE 3.x framework atop Bootstrap 4
* Created reusable cards for satellite and transmitters
* Cards and Modals are organized into subdirectories for template includes and base templates, respectively
* New stats display widgets using BS4 and AdminLTE 3
* Satellite search is redesigned and now accessible from any page of the site
* Introduced datatables for an "All Satellites" view and a modification of the new "All Transmitters" view
* Focus on all UI scaling down to mobile devices
* New model created for Operator (/ Owner): name, names, description, website
* Added django-countries for support of CountryField
* Satellite model expanded to include: Operator, (satellite) website, countries, launched datetime, deployed datetime
* Transmitter suggestions can now be approved in the UI by superusers
* Satellite entries can now be edited in the UI by users with the change satellite permission
* Satellite page is now broken into 'tabbed' panels (Profile, Map, Transmitters, etc) - with the tab menu options appearing in the sidebar or at the top depending on screen size
* Other cleanup and changes that I'm missing for sure.
Signed-off-by: Corey Shields <cshields@gmail.com>