Description:

Stubs out a new metric. Passes the metirc name, either CamelCased or
under_scored, and an optional named arguments defining values.

This generates a metric class in app/metrics.

Example:

rails generate metricky:metric TotalUsers --scope User --period day --type count

creates a Metricky metric class:
    Metric:     app/metrics/total_users_metric.rb