Exit when environment clashes are detected

When running kolla-ansible using a Kayobe environment, write the
environment name to $KOLLA_CONFIG_PATH/.environment. In later
executions, check that the environment name is the same. Warn user to
clean up $KOLLA_CONFIG_PATH otherwise.

Change-Id: Ibbb1fdcad4034620ff8fbfe184d803bcc86f53f9
Story: 2002009
Task: 42185