Revert D21064653: Remove the post install step

Differential Revision:
D21064653

Original commit changeset: da56d0754d91

fbshipit-source-id: 1086cfdeca9aa3830370ea115ba7b5f05d3fb124

Author: elicwhite

scripts/react_native_pods.rb

@@ -88,3 +88,14 @@ def use_flipper!(versions = {})
   pod 'FlipperKit/FlipperKitLayoutTextSearchable', versions['Flipper'], :configuration => 'Debug'
   pod 'FlipperKit/FlipperKitNetworkPlugin', versions['Flipper'], :configuration => 'Debug'
 end
+
+# Post Install processing for Flipper
+def flipper_post_install(installer)
+  installer.pods_project.targets.each do |target|
+    if target.name == 'YogaKit'
+      target.build_configurations.each do |config|
+        config.build_settings['SWIFT_VERSION'] = '4.1'
+      end
+    end
+  end
+end

template/ios/Podfile

@@ -18,6 +18,9 @@ target 'HelloWorld' do
   # Note that if you have use_frameworks! enabled, Flipper will not work and
   # you should disable these next few lines.
   use_flipper!
+  post_install do |installer|
+    flipper_post_install(installer)
+  end
 end
 
 target 'HelloWorld-tvOS' do