0.38.0.beta.1

Breaking

• Deprecate the xcconfig attribute in the Podspec DSL, which is replaced by
  the new attributes pod_target_xcconfig and user_target_xcconfig.
  Marius Rackwitz
  CocoaPods#3465

Enhancements

• Add support for specifying the CocoaPods version in the podspec.
  Daniel Tomlinson
  Core#240
• Attempt to detect (and warn) when a podfile has smart quotes.
  Samuel Giddins
• Add watchos as a new platform.
  Boris Bügling
  Core#249