Update to iOS 12

[guadaran]

Reference:

Summary: More and more classes are moved from public XCTest framework to private XCTAutomationSupport one. It is not big of an issue, however in order to be able to compile WDA with new XCode we need to either:

• explicitly link both frameworks (this diff)
• or remove direct class allocations Direct linking would remove requirement for future refactoring that might be necessary with potentially other moved classes so going for this approach.

Description of the Development environment

• macOs High Sierra 10.13.6
• Xcode version 10.1
• iOS 12 and 12.1 in real devices and simulators

Private framework is added (XCTAutomationSupport.Framework), from the following path:

-/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/PrivateFrameworks/XCTAutomationSupport.framework

Public framework is added (XCTest.Framework), from Xcode wizard. Changes are made to the project. pbxproj file