解决 Please specify a platform for this target in your Podfile

# Uncomment the next line to define a global platform for your project
 platform :ios, '9.0'

target 'testing_gowtham' do
  # Comment the next line if you're not using Swift and don't want to use dynamic frameworks
  use_frameworks!

  # Pods for testing_gowtham
 pod 'Firebase/Core'
 pod 'Firebase/Firestore'

end