Create document capturing outage notification process for site rack maintanance

[lnevers@bbn.com]

A document is needed to capture the notification process for InstaGENI rack outages. Document should capture the notification process, notification targets (including site contacts). Also if appropriate, timing requirements should also be captured.

Current InstaGENI documentation is being written at ​http://www.protogeni.net/ProtoGeni/wiki, so it is assumed that this outage notification document will also be at the same location.