Remove WatchOS as a supported platform

Author: benjamin-tang-pusher

README.md

@@ -23,7 +23,6 @@ For tutorials and more in-depth information about Pusher Channels, visit our [of
 - iOS 13.0 and above
 - macOS (OS X) 10.15 and above
 - tvOS 13.0 and above
-- watchOS 6.0 and above
 
 ### Legacy OS support