Add synchronous tests.

Even though we can not generally assert that events will be triggered synchronously, there is no reason event emitters comprising solely synchronous listeners should not be synchrnous.
Invent and use a method to avoid asynchronous promises.
Add sequential synchronous functions counter example.
Add same level synchronous tests for * and ** listeners as well.
Satisfy synchronous assumptions, but violate short circuit assumptions.
Using Promise.reduce to evaluate callbacks satisfies all tests.
Use Promise.reduce to implement chainExecutions.

This results in a slight loss of efficieny.
Add a failing test for synchronous ** events.
Fix synchronous callback for ** events.
Remove lint from index.
Flatten example.

With the synchronous constraints, the example doesn't need to use the promise structure.
Merge pull request #1 from plediii/enhance_synchronous

Enhance synchronous