Mark Prophetstor Driver Unsupported

The Prophetstor Driver 3rd Party CI hasn't
reported in 188 days.  This does not meet the
requirements for Cinder's 3rd Party CI requirements.

As a result the driver is being marked unsupported in the
Train release and should be removed in the 'U' release if
the problems are not resolved.

Change-Id: I78fe008c3b715f14d61f3fcef4920db5ac037344

cinder/volume/drivers/prophetstor/dplcommon.py

@@ -668,6 +668,9 @@ class DPLCOMMONDriver(driver.CloneableImageVD,
     # ThirdPartySystems wiki page
     CI_WIKI_NAME = "ProphetStor_CI"
 
+    # TODO(jsbryant) Remove driver in the 'U' release if CI is not fixed.
+    SUPPORTED = False
+
     def __init__(self, *args, **kwargs):
         cert_path = None
         cert_verify = False

doc/source/reference/support-matrix.ini

@@ -248,7 +248,7 @@ driver.nexenta=complete
 driver.nfs=complete
 driver.nimble=complete
 driver.oracle_zfssa=complete
-driver.prophetstor=complete
+driver.prophetstor=missing
 driver.pure=complete
 driver.qnap=complete
 driver.quobyte=complete

releasenotes/notes/unsupport-prophetstor-bfbc674fd86303db.yaml

@@ -0,0 +1,14 @@
+---
+upgrade:
+  - |
+    The Prophetstor driver has been marked as unsupported and is now
+    deprecated. ``enable_unsupported_driver`` will need to be set
+    to ``True`` in the driver's section in cinder.conf to continue
+    to use it.
+deprecations:
+  - |
+    The Prophetstor driver has been marked as unsupported and is now
+    deprecated. ``enable_unsupported_driver`` will need to be set
+    to ``True`` in the driver's section in cinder.conf to continue
+    to use it. If its support status does not change, it will be
+    removed in the 'U' development cycle.