Adds help option to reviewbot
Adds help option to reviewbot

Change-Id: If84821640c2cc4cc05c7788a7d0e0cc7c25607fe

redhat-openstack/rdo-infra,redhat-openstack/rdo-infra,rdo-infra/ci-config,rdo-infra/ci-config,rdo-infra/ci-config,redhat-openstack/rdo-infra,rdo-infra/ci-config,redhat-openstack/rdo-infra