Serverless 3.0.0 option type requirement

[benarena]

When running sls package:

Serverless: Deprecation warning: CLI options definitions were upgraded with "type" property (which could be one of "string", "boolean", "multiple"). Below listed plugins do not predefine type for introduced options:
             - Remover for "verbose"
            Please report this issue in plugin issue tracker.
            Starting with next major release, this will be communicated with a thrown error.
            More Info: https://www.serverless.com/framework/docs/deprecations/#CLI_OPTIONS_SCHEMA

See:
https://www.serverless.com/framework/docs/deprecations/#CLI_OPTIONS_SCHEMA
https://www.serverless.com/framework/docs/providers/aws/guide/plugins#defining-options

This should be a trivial update to the 'verbose' option.

[coyoteecd]

@benarena fyi I reimplemented this plugin as described in #22 and removed the verbose option, thus solving the deprecation warning. So if you don't really use that option, feel free to switch.