Tests

Fixed error on compilation of SpectrogramFlatView/UIColor+intermediate.swift for macOS #65

Job	Run time
Test / Create Swift Test Matrix	5s
Test / xcodebuild test (ios, swift 5.7)	3m 53s
Test / swift test (macos, swift 5.7)	1m 43s
Send Notification	0s
	5m 41s

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