Mobile v2.0 (Phase 1)

Phase 1 of Mobile v2.0 will include:

First Impressions	Priority
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1593016342	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1592983605	P0
Authentication
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1549434898	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1549533187	P1
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1561395204	P1
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1561296899	P3
Navigation
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1508376633	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1053360129	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1053327496	P1
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1053491267	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1053327503	P0
Main Tab Screens
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1565294657	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1565196370	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1561297028	P0
Other UI Updates
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1565294650	P0
https://mattermost.atlassian.net/wiki/spaces/MSU/pages/1561526431	P1
Global banners - do we change this based on new update	P1
Updates to Share Extension to support multi-server	P1
Message Input Improvements	P2