Merge pull request #37 from YusukeKinoshita/UIchange

U ichange
Merge pull request #38 from YusukeKinoshita/UIchange

tutorials/show/slidesページ作った
Merge pull request #39 from YusukeKinoshita/UIchange

いろいろUIととのえました
Merge pull request #40 from YusukeKinoshita/UIchange

render portfolios and tutorials at category/index
Add SNS widget
Merge pull request #41 from YusukeKinoshita/sns

Add SNS widget
Making Like Function For Tutorial
Merge pull request #42 from YusukeKinoshita/like

Making Like Function For Tutorial
favorite機能プルリクする前
conflict fixed