Fix stride error

#19

Prevent negative layout results in case the available width is zero

Thanks to @danurna 👏 for fixing that in #17

Fix width when popping back from ViewController

Fix width when popping back from ViewController and expanding width.

Thanks @hyouuu for suggesting a fix in #7.

Announce compatibility with watchOS 6+

0.4.0

Announce compatibility with watchOS 6+

Announce compatibility with macOS 10.15+ & tvOS 13+

Thanks @stevestreza