Adds dynamic Podfile lookup. Fixes the case where the Podfile does not
reside in the workspace's folder.

Beacuse the Pods project is always in the workspace and the
Podsproject contains the Podfile, xcode can be used to resolve the
filepath.
Merge pull request #25 from angerman/master

Adds dynamic Podfile lookup.
Merge branch 'master' into develop

* master:
  Adds dynamic Podfile lookup. Fixes the case where the Podfile does not reside in the workspace's folder.