Updates README.md to show the use of use_frameworks! (#216)
Updates README.md to show the use of use_frameworks! (#216)

Since `SwiftSupport.swift` was added to the source of this framework, Cocoapods installation breaks with the following error "Pods written in Swift can only be integrated as frameworks". The use of `use_frameworks!` is now obligatory.
material-foundation/ios-snapshot-test-case,peacemoon/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,facebook/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,onemedical/ios-snapshot-test-case,peacemoon/ios-snapshot-test-case,onemedical/ios-snapshot-test-case,Nuglif/ios-snapshot-test-case,onemedical/ios-snapshot-test-case,Nuglif/ios-snapshot-test-case,facebook/ios-snapshot-test-case,Nuglif/ios-snapshot-test-case,material-foundation/ios-snapshot-test-case,facebook/ios-snapshot-test-case,peacemoon/ios-snapshot-test-case