- updated plugin podspec to follow the latest Flutter template

ios/flutter_file_dialog.podspec

@@ -1,5 +1,6 @@
 #
-# To learn more about a Podspec see http://guides.cocoapods.org/syntax/podspec.html
+# To learn more about a Podspec see http://guides.cocoapods.org/syntax/podspec.html.
+# Run `pod lib lint test5.podspec` to validate before publishing.
 #
 Pod::Spec.new do |s|
   s.name             = 'flutter_file_dialog'
@@ -13,9 +14,10 @@ A new flutter plugin project.
   s.author           = { 'Your Company' => 'email@example.com' }
   s.source           = { :path => '.' }
   s.source_files = 'Classes/**/*'
-  s.public_header_files = 'Classes/**/*.h'
   s.dependency 'Flutter'
+  s.platform = :ios, '11.0'
 
-  s.ios.deployment_target = '11.0'
+  # Flutter.framework does not contain a i386 slice.
+  s.pod_target_xcconfig = { 'DEFINES_MODULE' => 'YES', 'EXCLUDED_ARCHS[sdk=iphonesimulator*]' => 'i386' }
+  s.swift_version = '5.0'
 end
-