Badges check feature
Using helper to refator code
Change router's name
Merge branch 'lee' into develop
Design nav style
Style the input area
Use flash to alarm if username is not found
Modify gemfile to use sinatra-flash
Merge branch 'lee' into develop
Use ajax to prevent from redirting after form submit
Delete unecessary router and template.

They used to display the result of checking badges. Now, we display the result at the same page.
Advise a little mistake
Merge branch 'lee' into develop
Merge branch 'develop'