Mark Datera driver unsupported

The Datera driver has not successfully run 3rd party CI for
a period greater than 60 days.  This falls out of the
Cinder requirements for 3rd Party CI.  As a result the
driver is being marked as unsupported in the Train release
and will be removed in the 'U' release if the problem is not
corrected.

Change-Id: If72c1430edfcb66e7d23c2c889b44c5459082414

cinder/volume/drivers/datera/datera_iscsi.py

@@ -99,6 +99,9 @@ class DateraDriver(san.SanISCSIDriver, api2.DateraApi, api21.DateraApi):
 
     HEADER_DATA = {'Datera-Driver': 'OpenStack-Cinder-{}'.format(VERSION)}
 
+    # TODO(jsbryant) Remove driver in the 'U' release if CI is not fixed.
+    SUPPORTED = False
+
     def __init__(self, *args, **kwargs):
         super(DateraDriver, self).__init__(*args, **kwargs)
         self.configuration.append_config_values(d_opts)

doc/source/reference/support-matrix.ini

@@ -196,7 +196,7 @@ notes=A vendor driver is considered supported if the vendor is
   accurate results. If a vendor doesn't meet this requirement
   the driver is marked unsupported and is removed if the problem
   isn't resolved before the end of the subsequent release.
-driver.datera=complete
+driver.datera=missing
 driver.dell_emc_powermax=complete
 driver.dell_emc_ps=complete
 driver.dell_emc_sc=complete

releasenotes/notes/datera-mark-unsupported-7b71d9124b3fded2.yaml

@@ -0,0 +1,14 @@
+---
+upgrade:
+  - |
+    The driver for Datera's Storage Systems 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 driver for Datera's Storage Systems 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.