Correct window position when tray is pushed aside

[riomarmccartney]

Expected Behavior

Current Behavior

The tray is pushed aside inside the menu bar on macOS, so when launching the tweet-tray window, it's pushed to the boundary of the screen. It should have a small padding between the side and the window, so that it doesn't look cut off.

Possible Solution

When the window is pushed aside & touching the border of the screen, it should have the same 20px spacing from the menu bar, between the window and the screen border.

Context

Better window placement

Your Environment

Develop branch

Software	Version(s)
Runtime	1.0.2
MacOS	10.13.3 (17D47)