Remove navbar border-radius and bottom margin
Rewording button in presentation section
Styling code challenges page

Using Coderay for syntax highlighting
Update heading style
Update style for code_challenges#show page
Add ability to edit and delete code challenge
Add Twitter share button to code_challenge#show
Only show action buttons for owner
Scoped code challenges by current user
Add call-to-action for user with no code challenge
Change time zone to Tokyo
Display code challenge submitter and time
Add short description for guest on show page
Add Google Analytics code
Redirect user back to original page

This to make it so that when user click on call-to-action button, they
will get redirected back to new code challenge page right away.