Merge pull request #497 from Iterable/MOB-3251-modify-podspec

[MOB-3251] add header_dir to podspec

Author: roninopf

Iterable-iOS-SDK.podspec

@@ -24,4 +24,6 @@ Pod::Spec.new do |s|
   s.swift_version = '5.3'
 
   s.resource_bundles = {'Resources' => 'swift-sdk/Resources/**/*.{storyboard,xib,xcassets,xcdatamodeld}' }
+
+  s.header_dir = 'IterableSDK'
 end