Fix proxy doesn't work by not using authentication

認証プロキシにしか対応していなかったのを修正
Fix default sort option doesn't work.

when it was not specfying default sort option, it returns api response.
Move comment to context message
Add test for default option
Change default sort option from n[ame] to do a[ll] (download)

実際使っていると、件数が多い場合こっちの方が便利な気がしてきたので変更
Add changelog
bumping
Merge branch 'master' of github.com:rochefort/gem-search