Fix typo on podspec

Author: jubril-paystack

Paystack.podspec

@@ -15,7 +15,7 @@ Pod::Spec.new do |s|
   s.requires_arc                   = true
   s.ios.deployment_target          = '11.0'
   s.swift_versions = '5.0'
-  ss.public_header_files = 'Paystack/Classes/PublicHeaders/*.h', 'Paystack/Classes/RSA/*.h'
+  s.public_header_files = 'Paystack/Classes/PublicHeaders/*.h', 'Paystack/Classes/RSA/*.h'
   s.source_files = 'Paystack/Classes/**/*.{swift,h,m}'
   s.resources = 'Paystack/Resources/**/*'