add an initial ssh config file to ignore known hosts
diff --git a/ansible/roles/common/files/ssh-config b/ansible/roles/common/files/ssh-config
new file mode 100644
index 0000000..df88259
--- /dev/null
+++ b/ansible/roles/common/files/ssh-config
@@ -0,0 +1,3 @@
+Host *
+    StrictHostKeyChecking no
+    UserKnownHostsFile=/dev/null