Issue #575

Create Objc target

Check runtime

Check for example _runtime(_ObjC) or os(macOS if you plan to use platform specific feature

For example, in test we use XCTest which is run via Xcode and is a macOS framework, so we need to check for os(macOS)

Note that in Objc framework, the header files must be in include folder

targets: {
        var targets: [Target] = [
                name: "QuickTests",
                dependencies: [ "Quick", "Nimble" ],
                exclude: [
#if os(macOS)
        targets.append(contentsOf: [
            .target(name: "QuickSpecBase", dependencies: []),
            .target(name: "Quick", dependencies: [ "QuickSpecBase" ]),
        targets.append(contentsOf: [
            .target(name: "Quick", dependencies: []),
        return targets