cache script 1-4
Merge pull request #858 from code-dot-org/cache-course1-4

cache scripts for course 1-4
Merge pull request #859 from code-dot-org/staging

DTT
Update README.md
Merge pull request #860 from code-dot-org/staging

Update README.md
Merge pull request #861 from code-dot-org/test

DTP