Web EasEvents: Role based authentication

* Added ability
* Added Hirb gem for table structuring on rails console.
* Added necessary configurations for Role based authentication using cancan.
* Made seeds.rb file with the neccesary prerequisite data.

ToDo:
* Need to add access controls for various actions in views and controllers in accordance to difference roles possible.
Merge pull request #31 from slade1/vipul_role_based_auth

Role Based Auth by cancan.