Exit with a non-zero code when database connection fails

[khawaga]

I've noticed that when the database connection returns an error the CLI still exits with status 0. This is a bit confusing as the connection failed and migrations were not run. I believe the program should exit with an error status such as 1.

This would be helpful when running migrations in a CI environment for example or in other cases where you'd like to break execution if the migrations were not applied.