Use github releases and publish .ipa file

[emanuelb]

Add .ipa file in assets in github releases & add description of the release in:
https://github.com/breadwallet/breadwallet-ios/releases
also latest tag is appstore-4.8.1:
https://github.com/breadwallet/breadwallet-ios/releases/tag/appstore-4.8.1
while the version in applestore is 4.9:
https://apps.apple.com/us/app/id885251393
so tag the realted commit, and upload the .ipa file in github releases as well.