Mark betas as only having "preliminary testing"

Author: gabebear

README.md

@@ -13,10 +13,10 @@ Install and debug iOS apps from the command line. Designed to work on un-jailbro
 
 #### Tested Configurations
 The ios-deploy binary in Homebrew should work on macOS 10.0+ with Xcode7+. It has been most recently tested with the following configurations:
- - macOS 10.14 Mojave, 10.15 Catalina, and 11.0b BigSur
- - iOS 13.0 and iOS 14.0b
- - Xcode 11.3, 11.6, 12.0b3
- - x86 and Arm64e based Apple Macintosh Computers
+ - macOS 10.14 Mojave, 10.15 Catalina and preliminary testing on 11.0b BigSur
+ - iOS 13.0 and preliminary testing on iOS 14.0b
+ - Xcode 11.3, 11.6 and preliminary testing on Xcode 12 betas
+ - x86 and preliminary testing on Arm64e based Apple Macintosh Computers
 
 ## Roadmap