Add xcuserdata to .gitignore

ultramiraculous · ultramiraculous · commit 69210ca3c453 · 2016-04-06T14:04:15.000-07:00
When using PromiseKit as a subproject, Xcode keeps adding xcuserdata folders. If you're using git submodules it means that the submodule is perpetually considered out of sync while you're developing.
diff --git a/.gitignore b/.gitignore
@@ -1,3 +1,4 @@
 /Carthage
 /Cartfile.resolved
 /Build
+*.xcodeproj/xcuserdata/
