try and fix bad cassandra apt-get update on azure ubuntu 16.04 vm

.ci/ansible_tests.py

@@ -66,6 +66,10 @@ with ci_lib.Fold('job_setup'):
     ci_lib.dump_file(inventory_path)
 
     if not ci_lib.exists_in_path('sshpass'):
+        # fix errors with apt-get update
+        run("sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys 78BD65473CB3BD13")
+        run("sed -i -e 's#deb https://downloads.apache.org/cassandra/debian 39x main#deb http://downloads.apache.org/cassandra/debian 39x main#g' /etc/apt/sources.list.d/39x.list")
+
         run("sudo apt-get update")
         run("sudo apt-get install -y sshpass")