Update RxSwift to 4.3.0

gin0606 · gin0606 · commit a9f99b38fd0d · 2018-09-18T14:50:05.000+09:00
diff --git a/Cartfile.resolved b/Cartfile.resolved
@@ -1,3 +1,3 @@
 github "Quick/Nimble" "v7.1.2"
 github "Quick/Quick" "v1.3.0"
-github "ReactiveX/RxSwift" "4.2.0"
+github "ReactiveX/RxSwift" "4.3.0"
