Add statsd sample rate compat

[sj26]

statsd-ruby takes a simple numeric argument for sample rate:

  # Sends an increment (count = 1) for the given stat to the statsd server.
  #
  # @param [String] stat stat name
  # @param [Numeric] sample_rate sample rate, 1 for always
  # @see #count
  def increment(stat, sample_rate=1)
    count stat, 1, sample_rate
  end

The datadog statsd version only takes sample rate as a keyword option:

    # Sends an increment (count = 1) for the given stat to the statsd server.
    #
    # @param [String] stat stat name
    # @param [Hash] opts the options to create the metric with
    # @option opts [Numeric] :sample_rate sample rate, 1 for always
    # @option opts [Array<String>] :tags An array of tags
    # @option opts [Numeric] :by increment value, default 1
    # @see #count
    def increment(stat, opts={})
      incr_value = opts.fetch(:by, 1)
      count stat, incr_value, opts
    end

The datadog statsd instance doesn't quite provide drop-in compatibility given this argument. We're using a Datadog Statsd instance as a Statsd instance to pass into a third party gem and it uses this argument. Adding compatibility here seems reasonable?

Thanks!

[masci]

This LGTM, thanks for your PR!

[sj26]

Thanks @masci! What’s your release schedule like?

[masci]

We don't have an actual release schedule, assuming this is blocking the issue on Sidekiq I guess this can go out asap as 3.2.0.
Will make the release before the end of the week, even today if I manage to get some bandwidth.

[mperham]

I'm going to be rolling out Sidekiq Pro 3.6.1 soon which fixes this issue on my end.

[masci]

3.2.0 is out 🎉