fix broken get last release version function if curl UA is set to
curl -A "Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0)" 'https://api.github.com/repos/steeve/boot2docker/releases'
this will return a JSON with windows line feeds
add more error handling
Merge pull request #107 from aheissenberger/fix/pull/get-latest-release-wrong-ua

boot2docker / fix broken get last release version function if curl UA is set to IE