Determining TravisCI enviroment

TravisCI.swift

class TravisCI {

    /*
     * check whether test is running on TravisCI or not using TravisCI enviroment variables.
     *
     * as for TravisCI enviroment variables availables @see https://docs.travis-ci.com/user/environment-variables/#Default-Environment-Variables
     *
     */
    static var isRunningOnTravisEnviroment: Bool {
        let isTravisEnviromentVariableName = "CI"
        let isCIEnviromentVariableName = "TRAVIS"
        let enviromentVariables = ProcessInfo().environment
        
        if
            enviromentVariables.keys.contains(isCIEnviromentVariableName), enviromentVariables[isCIEnviromentVariableName] == "true",
            enviromentVariables.keys.contains(isTravisEnviromentVariableName), enviromentVariables[isCIEnviromentVariableName] == "true" {
            return true
        }
        
        return false
    }
}