Delete Alcatraz.xccheckout. Related to PR #82.

Remove the Alcatraz.xccheckout file from the repository as it produces noise each time a PR is merged and is now ignored by git since PR #82.
Important note: This will also delete your local Alcatraz.xccheckout file upon pull. Make a backup! ;)
Merge pull request #87 from guillaume-algis/patch-1

Delete Alcatraz.xccheckout. Related to PR #82.