def db_config
      @db_config ||= begin
        opts = OptionsHash.new(YamlConfig.user_config.options)
        opts.merge!(YamlConfig.local_config.options)
        opts.merge!(EnvConfig.new.options)
        opts
      end
    end
def db_config
      @db_config ||= begin
        opts = OptionsHash.new(YamlConfig.user_config.options)
        opts.merge!(YamlConfig.local_config.options)
        opts.merge!(EnvConfig.new.options)
        opts
      end
    end
Grabs the database options from
  - ~/.config/sequelizer.yml if it exists
  - config/database.yml if it exists
  - environment variables (also reads from .env)