ignore certs in travis ansible-galaxy install

Signed-off-by: Sebastian Gumprich <github@gumpri.ch>

Author: Sebastian Gumprich

.travis.yml

@@ -58,7 +58,7 @@ script:
   - 'docker run --detach --volume="${PWD}":/etc/ansible/roles/ansible-mysql-hardening:ro ${run_opts} rndmh3ro/docker-${distro}-ansible:${version} "${init}" > "${container_id}"'
 
   # Install ansible galaxy requirements
-  - 'docker exec "$(cat ${container_id})" ansible-galaxy install -r /etc/ansible/roles/ansible-mysql-hardening/requirements.yml -p /etc/ansible/roles/'
+  - 'docker exec "$(cat ${container_id})" ansible-galaxy install -c -r /etc/ansible/roles/ansible-mysql-hardening/requirements.yml -p /etc/ansible/roles/'
 
   # Test role.
   - 'travis_wait docker exec "$(cat ${container_id})" ansible-playbook /etc/ansible/roles/ansible-mysql-hardening/default.yml'