Fix bug: if RemoteRunnable doesn't contains BuildableReference XcodeProj removes xcscheme file

[subdan]

Resolves #626

Short description 📝

I have fixed 2 bugs:

1. if RemoteRunnable tag doesn't contains BuildableReference tag XcodeProj removes xcscheme file.
2. Xcode 12 generates askForAppToLaunch = "Yes". XcodeProj doesn't parse this argument because value is not YES.

Solution 📦

Inside XCScheme+Runnable.swift made buildableReference property optional.

public var buildableReference: BuildableReference?

Also replaced the following line:

element.addChild(buildableReference.xmlElement())

with the next one:

if let buildableReference = buildableReference {
    element.addChild(buildableReference.xmlElement())
}

To fix the second bug I add $0 == "Yes" next after $0 == "YES"

askForAppToLaunch = element.attributes["askForAppToLaunch"].map { $0 == "YES" || $0 == "Yes" }

Implementation 👩‍💻👨‍💻

Detail in a checklist the steps that you took to implement the PR.

• Write unit tests
• Fixed an issue where xcscheme file was deleted
• Fixed another issue where askForAppToLaunch = "Yes" was not able to decode.

[pepicrft]

@all-contributors add @subdan for code

[allcontributors]

@pepibumur

I've put up a pull request to add @subdan! 🎉

[pepicrft]

Thanks a lot @subdan for this contribution.