add equals, hashCode, toString to Notifications
add equals, hashCode, toString to Notifications

zhongdj/RxScala,samuelgruetter/RxScala,joohnnie/RxScala,zjrstar/RxScala,samuelgruetter/RxScala,jbripley/RxScala,jbripley/RxScala,hermanbanken/RxScala,hermanbanken/RxScala,TracyLu/RxScala,ReactiveX/RxScala