Code.org homepage studio bar improvements..
- Show Flappy instead of shop for non-en users,
- Show shop icon even for phone (<= 600px wide) users.
Merge pull request #891 from code-dot-org/homepageshop

Code.org homepage studio bar improvements..
Merge pull request #892 from code-dot-org/staging

DTT
Merge pull request #893 from code-dot-org/test

DTP