Home Screen Tab switch animation

The `EditText` along the bottom of the home screen (for joining/creating a group) should animate down then reappear as the tab is switched. i.e:
- In `Joined` tab, the bottom bar displays an option to join a group
- Switch to the `Created` tab
- the bottom bar with the option to join a group should animate down, and then a bar with an option to create a group should animate back into place. The join and create bottom bars have different colors.