Switch source code URL in podspec from ssh to https

https://trello.com/c/BRWugSrG/382-switch-url-in-podspec-to-use-html-url-instead-of-ssh-url-for-devs-who-don-t-already-have-their-keys-in-github-com
sdk DWpZlQXd - Add support for PayPal app correlation ID
Merge remote-tracking branch 'public/master'
Add date to CHANGELOG for 3.0.1 release
Bump pod version to 3.0.1
sdk project - Fix PayPal Acceptance Spec