CocoaPods sample to fix compilation

fix-cocoapods.rb

post_install do |installer|

  targetsMap = {
    '4.0': [
      'BetterSegmentedControl',
      'Dwifft',
      'JTAppleCalendar',
      'MessageKit',
      'PKHUD',
      'RxCocoa',
      'RxSwift',
      'RxSwiftExt',
      'SkyFloatingLabelTextField'
    ],
    '4.1': [
      'DifferenceKit',
      'EasyPeasy',
      'LayoutKit',
      'Realm',
      'RealmSwift'
    ]
  }

  installer.pods_project.targets.each do |target|
    targetsMap.each do |swift_version, targets|
      if targets.include? target.name
          target.build_configurations.each do |config|
              config.build_settings['SWIFT_VERSION'] = swift_version
          end
      end
    end
  end
end