New Command: Hardware notifications

[allmightyspiff]

• slcli hardware notifications [hardware_id]
  Shows who gets notified when the server has a monitoring issues. https://sldn.softlayer.com/reference/services/SoftLayer_User_Customer_Notification_Hardware/findByHardwareId/
• slcli hardware add-notification [hardware_id] [user_id]
  Add a user to be notified if this server has a monitoring issues. https://sldn.softlayer.com/reference/services/SoftLayer_User_Customer_Notification_Hardware/createObject/ Might want to be able to specify multiple user Ids as well.

Do the same for virtual servers as well.
https://sldn.softlayer.com/reference/services/SoftLayer_User_Customer_Notification_Virtual_Guest/ is basically the same api

Basically this page from the portal:

https://cloud.ibm.com/gen1/infrastructure/monitoring/1403539/bare-metal