Adds a podspec for CocoaPods support

RNAWSCognito.podspec

@@ -0,0 +1,19 @@
+# coding: utf-8
+Pod::Spec.new do |s|
+  s.name    = "RNAWSCognito"
+  s.version = "1.29.0"
+  s.requires_arc = true
+  s.platforms = { :ios => "8.0" }
+  s.license = { :file => 'LICENSE.txt' }
+  s.homepage = "https://github.com/aws/amazon-cognito-identity-js"
+  s.author = "Amazon"
+
+  s.summary = "Amazon Cognito Identity SDK for JavaScript"
+  s.description = <<-DESC
+                    The Amazon Cognito Identity SDK for JavaScript allows JavaScript enabled applications to sign-up users, authenticate users, view, delete, and update user attributes within the Amazon Cognito Identity service.
+                  DESC
+
+  s.source = { :git => "https://github.com/aws/amazon-cognito-identity-js.git", :tag => s.version.to_s }
+  s.source_files     = 'ios/RNAWSCognito.{h,m}'
+  s.dependency 'JKBigInteger2', '0.0.5'
+end