Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1443804

Description of problem:

There is not hammer command to enable/disable notifications
for a particular host.

This feature is available in GUI:
1) Hosts > All Hosts > Tick host >Select Action > Disable Notification
2) Hosts > All Hosts > Tick host >Select Action > Enable Notification

How reproducible:
#hammer host update --help
#hammer host create --help

Actual results:
No option available to enable/disable notifications for a host via hammer cli.

Expected results:
#hammer host update --name <hostname> --notifications <enable/disable>