Issue title: Is fastlane compatible with xcode 9?
 Issue body: I changed my commandline version of xcode to 9.0 and my projects timeout when running fastlane. Is this because its not supported yet?
 Comments: 
 Comment 0: It seems like you have not included the output of `fastlane env`

To make it easier for us help you resolve this issue, please update the issue to include the output of `fastlane env` :+1:
 Comment 1: Yeah, it's mostly working with the exception of screenshots. 
Please file any issues you see, as we're trying to make sure it works 💯 
👍 
 Comment 2: @taquitos what is the best issue to follow for the screenshots work?
 Comment 3: The PR we're working on is: https://github.com/fastlane/fastlane/pull/9570
I think because there are so many issues, it's best to just watch that PR 😄 
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