Merge pull request #11 from jsgirls/development

Add material page
Merge pull request #14 from jsgirls/development

sync to master
Merge branch 'development' of github.com:jsgirls/jsgirls.org
Merge branch 'development' of github.com:jsgirls/jsgirls.org
Merge branch 'development' of github.com:jsgirls/jsgirls.org
Merge branch 'development' of github.com:jsgirls/jsgirls.org
Fix number of tutor for Sapporo#1
Merge pull request #18 from tricknotes/fix-number-of-tutor-for-sapporo

Fix number of tutor for Sapporo#1
typo