Update default SDK for iOS and tvOS

fastlane/.env.default

@@ -1,6 +1,6 @@
-AF_IOS_SDK=iphonesimulator11.2
+AF_IOS_SDK=iphonesimulator11.3
 AF_MAC_SDK=macosx10.13
-AF_TVOS_SDK=appletvsimulator11.2
+AF_TVOS_SDK=appletvsimulator11.3
 
 AF_CONFIGURATION=Release