Unable to find Xcode app path if the path contains a space

Issue: https://github.com/appium/appium/issues/1233

**NOTE:** I haven't run any of the unit or functional tests on this branch.  I've never used mocha before, and unfortunately, I don't currently have the bandwidth to figure it out.  Please feel free to add commits for any test changes and pull this PR whenever.

@jlipps