Fix for mandatory User Agent for Github API 

Github has made it mandatory for API requests to be accompanied with a meaningful User Agent header. 
http://developer.github.com/changes/2013-04-24-user-agent-required/
Also logging response in case of API failures - will make it easier to manage API changes.
missing update param; error message; typo
Merge pull request #3 from gordonwoodhull/fixes

Fixes