[FIX][BUG] Hotfix before initial v2 release.

[NEW] Support sending message using SDK

[NEW] Show message list using SDK (pure online)

- Checks if the server url is valid before connection.
- Replaces rounded avatar to avatar with rounded corners.

Merge branch 'develop-2.x' of https://github.com/RocketChat/Rocket.Chat.Android into feature/show-message-list-using-sdk

[NEW] Listen to Room and Subscription changes

[NEW] Spotlight (local data)

[NEW] Integrated GCM and added notifications support

Retrieve public settings on login screens

generated google-services.json file including chat.rocket.android.dev
app within clients

- in memory repository for settings for now (will move to DB)
- repository and interactors for Current server

Remove the SDK as an module

[NEW] Show list of chats using the SDK (pure online)

Develop-2.x

[LAYOUT] Finishing authentication screens