zevarito/mixpanel — pull request #116 by ericboehs (2013-08-17 23:31:00+00:00)
Title: Track events weren't being sent asynchronously

Since `options[:async]` is usually `nil` and because we aren't merging `defaults` on to `options` (as we are in [person.rb](https://github.com/zevarito/mixpanel/blob/master/lib/mixpanel/person.rb#L70)), `options[:async]` was `nil` and causing events to be tracked synchronously.