Show progress when updating app

Issue: #5 #6
When updating show changelog

Firstly look for changelog on the kanso configuration in base64 encoded markdown. If none found, look for a Changes.md file at the root of the github repository.
Merge branch 'update-app-progress' into update-app-progress-2
Merge pull request #72 from garden20/update-app-progress-2

Update app progress