Type checking for configuration #24
Description
Is your feature request related to a problem? Please describe.
It would be really nice if a user could have their configuration validated before committing it and hoping to run a migration.
Describe the solution you'd like
Type checking should be optional (maybe the user knows better than we do what they want, it's their migration after all). It would also be nice if we included a task like rake ghost_adapter:validate_config that would just type-check the configuration and return.