Feature/examples (#9)
Feature/examples (#9)

* Adds exmple usage of express-acl

* Adds exmple usage of express-acl

* Adds exmple usage of express-acl

* Fixing houndci issues

* Fix codeclimate issue

* Adds validate method

andela-thomas/express-acl,nyambati/express-acl,egorbenko/express-acl