Add Sahara project deadlines for Queens

As agreed upon at Denver PTG.

Change-Id: I7060c38b1f172a1aad9f3a2b465799081c240435

doc/source/queens/schedule.rst

@@ -349,3 +349,19 @@ Cinder Feature Proposal Freeze
 
 All new Cinder features must be proposed and substantially complete, with unit
 tests by 19 Jan, 2018 (23:59 UTC).
+
+
+Sahara
+------
+
+.. _q-sahara-plugin-deadline:
+
+Sahara Plugin Deadline
+^^^^^^^^^^^^^^^^^^^^^^
+
+The deadline for submitting new plugins or plugin versions to Sahara is
+8 Dec 2017 (23:59 UTC). The motivation for this deadline is to ensure
+sufficient time for testing plugins and ensuring their stability. Also, due to
+the unpredictable release schedule of Hadoop components, we should avoid the
+practice of delaying plugin upgrades too far into the cycle. Exemptions to this
+deadline may be granted by the PTL.

doc/source/queens/schedule.yaml

@@ -72,6 +72,7 @@ cycle:
   - q-manila-driver-deadline
   - q-cinder-driver-deadline
   - q-cinder-spec-freeze
+  - q-sahara-plugin-deadline
 - end: '2017-12-15'
   name: R-11
   start: '2017-12-11'