Pr/74 : Dynamic ReQL Example

[bchavez]

Supersedes #74 , dynamic query unit test passing.

Added test_dynamically_generated_query as a result of our discussion on Slack.

/cc @jjonesrs

:car: :bluecar: [**"Let the good times roll..."**_](https://www.youtube.com/watch?v=7BDBzgHXf64)

[bchavez]

@jjonesrs , we good?

Unit tests be passin':

https://github.com/bchavez/RethinkDb.Driver/blob/master/Source/RethinkDb.Driver.Tests/ReQL/Examples.cs#L318

peace homies :v:

:cloud: :sunny: Bassnectar - Chasing Heaven - Into the Sun

[jjonesrs]

@bchavez Yup, we're good! Thank you for the timely and helpful responses. :+1: