update podspec

Author: NSProgrammer

TwitterImagePipeline.podspec

@@ -1,6 +1,7 @@
 Pod::Spec.new do |s|
   s.name             = 'TwitterImagePipeline'
   s.version          = '2.11.0'
+  s.compiler_flags   = '-DTIP_PROJECT_VERSION=2.11.0'
   s.summary          = 'Twitter Image Pipeline is a robust and performant image loading and caching framework for iOS'
   s.description      = 'Twitter created a framework for image loading/caching in order to fulfill the numerous needs of Twitter for iOS including being fast, safe, modular and versatile.'
   s.homepage         = 'https://github.com/twitter/ios-twitter-logging-service'