Open Stack

TLDR; moving Magnum to match upstream release scheduling intersecting k3

As discussed in our last IRC meeting we want to merge our Magnum 
milestone schedules with the upstream OpenStack schedules as soon as 
feasible.  We think it is feasible to merge release schedules for K3.  
As such, We have picked the following dates for our schedules:

Milestone #2:February 16th
Milestone #3 - merging with all OpenStack K3: March 19th
magnum rcs April 9th-23rd
magnum-2015.1 release - April 30th

 From k3 forward, we will follow the Kilo release schedule here:

https://wiki.openstack.org/wiki/Kilo_Release_Schedule