Added an error message for when a migration is attempted and the migrationFile on the database configuration is null. This preempts an unhelpful NPE from inside of Liquibase.
Don't exit with error for db command.

Update the CLI handling to not exit with a return code of 1 when
processing the "db" subcommand.
Merge pull request #6 from alexwen/master

Added an error message for migration without a migrationFile
Merge pull request #7 from pkwarren/better_cli_handling

Don't exit with error for db command.
bumping to .14