Swift 4.2

[DmitryPR]

This is the same PR as #199 but has the travis configuration changed to the xcode 10.1

[DmitryPR]

I can see the tests passing but there is a random error with Xcode 10.1
microsoft/azure-pipelines-tasks#8840

2019-01-17 10:06:18.590 xcodebuild[2430:8509] *** Assertion failure in ROCKRemoteProxy * _Nullable rock_XPCObjectToROCKRemoteProxy(xpc_object_t _Nonnull __strong, ROCKSessionManager * _Nonnull __strong, NSError * _Nullable __autoreleasing * _Nullable)(), /BuildRoot/Library/Caches/com.apple.xbs/Sources/ROCKit/ROCKit-24/ROCKit/ROCKRemoteProxy+ROCK.m:97 ** INTERNAL ERROR: Uncaught exception ** Uncaught Exception: Invalid parameter not satisfying: sessionManager Stack: Invalid connection: com.apple.coresymbolicationd 0 __exceptionPreprocess (in CoreFoundation) 1 objc_exception_throw (in libobjc.A.dylib) 2 +[NSException raise:format:arguments:] (in CoreFoundation) 3 -[NSAssertionHandler handleFailureInFunction:file:lineNumber:description:] (in Foundation) 4 rock_XPCObjectToROCKRemoteProxy (in ROCKit) 5 rock_NSDictionaryDeserializer (in ROCKit) 6 rock_XPCObjectToNSObject (in ROCKit) 7 __rock_XPCObjectToNSDictionary_block_invoke (in ROCKit) 8 _xpc_dictionary_apply_apply (in libxpc.dylib) 9 _xpc_dictionary_apply_node_f (in libxpc.dylib) 10 xpc_dictionary_apply (in libxpc.dylib) 11 rock_XPCObjectToNSDictionary (in ROCKit) 12 rock_XPCObjectToNSError (in ROCKit) 13 simservice_send_request_sync (in CoreSimulatorUtilities) 14 -[SimDevice _onBootstrapQueue_shutdownWithError:] (in CoreSimulator) 15 __64-[SimDevice shutdownAsyncWithCompletionQueue:completionHandler:]_block_invoke (in CoreSimulator) 16 __67-[SimDevice bootstrapQueueAsync:completionQueue:completionHandler:]_block_invoke (in CoreSimulator) 17 _dispatch_call_block_and_release (in libdispatch.dylib) 18 _dispatch_client_callout (in libdispatch.dylib) 19 _dispatch_queue_serial_drain (in libdispatch.dylib) 20 _dispatch_queue_invoke (in libdispatch.dylib) 21 _dispatch_root_queue_drain_deferred_wlh (in libdispatch.dylib) 22 _dispatch_workloop_worker_thread (in libdispatch.dylib) 23 _pthread_wqthread (in libsystem_pthread.dylib) 24 start_wqthread (in libsystem_pthread.dylib) /Users/travis/.travis/job_stages: line 104: 2430 Abort trap: 6 xcodebuild -workspace Locksmith.xcworkspace -scheme "$SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Release ONLY_ACTIVE_ARCH=NO test 2431 Done | xcpretty -c The command "if [ $RUN_TESTS == "YES" ]; then xcodebuild -workspace Locksmith.xcworkspace -scheme "$SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Release ONLY_ACTIVE_ARCH=NO test | xcpretty -c; fi" exited with 134.