Swtich to mysql db. Not fully configured in fig
Removed specifying host port of 80 in case there are multiple web projects
- can use fig port web 3000 to find the host port allocated by fig
Reuse official rails image
Merge pull request #1 from zhao-li/feature/update_ports

Removed specifying host port of 80 in case there are multiple web projec...
Merge pull request #2 from zhao-li/feature/use_official_rails_image

Reuse official rails image
Fix mysql access issues
Avoid server.pid errors when restarting web container
Use data-only container
https://docs.docker.com/userguide/dockervolumes/#creating-and-mounting-a-data-volume-container
Merge branch 'feature/fix_mysql' into develop
Merge branch 'feature/data_only_container' into develop
Merge branch 'feature/rm_server_pid' into develop
Merge branch 'develop'