Fix linters failure due to etcd role

role linters task is failing with:
  "sorry, etcd was not found on galaxy.ansible.com."

Change-Id: I11a78c1578ca95aa6a712cf3b1797fdae2eaa5e2

tests/ansible-role-requirements.yml

@@ -42,6 +42,10 @@
   src: https://git.openstack.org/openstack/openstack-ansible-os_glance
   scm: git
   version: master
+- name: etcd # dependency of os_neutron role
+  scm: git
+  src: https://github.com/logan2211/ansible-etcd
+  version: master
 - name: os_neutron
   src: https://git.openstack.org/openstack/openstack-ansible-os_neutron
   scm: git