Add missed `_` for <em> tag in security.md
Merge pull request #25 from yui-knk/fix/security

Add missed `_` for <em> tag in security.md
Merge branch 'japanese' of github.com:yasslab/railsguides.jp into japanese
Publish Rails on Rack
Merge pull request #26 from yui-knk/translate/rack

Publish Rails on Rack
Merge branch 'japanese' of github.com:yasslab/railsguides.jp into japanese
Add CC-BY-SA image
Fix #27: Update license to CC-BY-SA 4.0
Fix layout break in README
Fix #28: wrong relationship in Association Basics
Add conjunction to express correct relationship between sentences
Remove unnecessary '*'
Merge pull request #29 from yui-knk/fix/i18n

Remove unnecessary '*'
Merge branch 'japanese' of github.com:yasslab/railsguides.jp into japanese