1)Added interface to being implemented for email class: Send, SendAsync and Cancel changed as ending methods.
2)Statics method/properties in email class changed to instace one.
3)Set Default SmtpClient from ctor instead FromDefault chained method.
4)Override Default SmtpClient from ctor instead UsingClient chained method.

Signed-off-by: hdiazburgos <dr.hectordiaz@gmail.com>
Minors code organizations.

Signed-off-by: hdiazburgos <dr.hectordiaz@gmail.com>
Fix Emai class ctor bug.

Signed-off-by: hdiazburgos <dr.hectordiaz@gmail.com>
Switch from MS Test to NUnit:
-Refactory tests for suit NUnit.Framework and IFluentEmail (interface) implementation.
-Added DeploymentItem  custom atribute to get equivalent solution for in NUnit.
Helpful post: http://feelings-erased.blogspot.com/2013/12/moving-to-nunit-from-mstest-experience.html

Signed-off-by: hdiazburgos <dr.hectordiaz@gmail.com>