Update git submodules
* Update docs/submodules/dovetail from branch 'master'
- bugfix: hosts info is wrongly processed
changes:
1. add usage example in hosts.yaml.sample
2. fix /etc/hosts from wrong format {'hostname': 'ip'} to
the right 'ip hostnames'
3. fix --add-hosts from wrong usage --add-host {'hostname': 'ip'} to
the right --add-host='hostnames':ip
4. support per ip mapping mutiple hostnames, which is also
in line with /etc/hosts schema
JIRA: DOVETAIL-556
Change-Id: I92e8cb0fd3476b61f5c73a69e34c4a66aef51d6e
Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>