Docs: Ensure OUTPUT_DIRECTORY exists before generating documentation. With an OUTPUT_DIRECTORY which is under a directory, like Docs/CocoaGit.docset, instead of directly under SOURCE_ROOT, like CocoaGit.docset, the Docs will fail to build. This change adds a test to see if the SOURCE_ROOT/OUTPUT_DIRECTORY exists and create it if it doesn't.
Docs: Ensure OUTPUT_DIRECTORY exists before generating documentation.
With an OUTPUT_DIRECTORY which is under a directory, like Docs/CocoaGit.docset, instead of directly under SOURCE_ROOT, like CocoaGit.docset, the Docs will fail to build. This change adds a test to see if the SOURCE_ROOT/OUTPUT_DIRECTORY exists and create it if it doesn't.

schacon/cocoagit,geoffgarside/cocoagit,schacon/cocoagit,geoffgarside/cocoagit