add release notes for proguard config
add release notes for proguard config

carlospontual/card.io-Android-source,lkorth/card.io-Android-source,lkorth/card.io-Android-source,lkorth/card.io-Android-source,lkorth/card.io-Android-source,carlospontual/card.io-Android-source,carlospontual/card.io-Android-source,carlospontual/card.io-Android-source,lkorth/card.io-Android-source,carlospontual/card.io-Android-source