v9.0.0-rc.3

BREAKING CHANGES

• Make postNotifications generic and usable with non-void closures #819
• Bump minimum iOS version to 9.0 #825
• [API BREAKING] Modify expect overloads to fix Swift 5.3 incompatibility #824

Improvements

• Set ENABLE_TESTING_SEARCH_PATHS to YES #803
• Test building for tvOS with Xcode-SwiftPM integration #818
• Add DSL tests for expect variants #823