Revert "Update README Doc"

This reverts commit 0022a0bec6a5407114acfaf6edc526d1f478e70b.
Revert 0022a0b..fa14f8c

This rolls back to commit 0022a0bec6a5407114acfaf6edc526d1f478e70b.
Update Gem File

Use sqlite3 in dev environment only, ignore push to heroku.