Added trait methods to store token in the session

Hi Resetters!

This release contains #143 from @jrushlow which introduces 2 new methods in ResetPasswordControllerTrait for storing the entire ResetPasswordToken object in the session. The purpose of this - see symfony/maker-bundle#785 - is to allow you to store the object in the session so that you can accurately show the expiration time on the next page.

Diff: v1.2.2...v1.3.0

Have fun!