SwiftCov 是一个可以产生 Swift 测试代码覆盖信息的工具。
用法：
$ swiftcov helpAvailable commands:
geneRATe Generate test CODE coverage files for your Swift tests
help Display general or command-SPEcific help
version Display the current version of SwiftCov
怎样运行实例项目：
$ Make install
$ cd Examples/ExampleFramework/
$ swiftcov generate --output coverage_iOS \
Xcodebuild test \
-project ExampleFramework.xcodeproj \
-scheme ExampleFramework-iOS \
-sdk iPhonesimulaTor \
-configuration Release