Update Gerrit hook command-line parameters

As of Gerrit 3.2, some hook command lines now include username
parameters of various sorts in addition to the IDs. Also
patchset-created no longer passes an --is-draft parameter, as that
is now no longer a Gerrit feature. Add the missing new parameters
and remove the defunct one.

Change-Id: I5808e1b3398926810ba0e54bf132a0adeac5d2ac
diff --git a/jeepyb/cmd/update_bug.py b/jeepyb/cmd/update_bug.py
index 34be79e..41ce8c9 100644
--- a/jeepyb/cmd/update_bug.py
+++ b/jeepyb/cmd/update_bug.py
@@ -305,16 +305,19 @@
     parser.add_argument('--commit', default=None)
     parser.add_argument('--topic', default=None)
     parser.add_argument('--change-owner', default=None)
+    parser.add_argument('--change-owner-username', default=None)
     # change-abandoned
     parser.add_argument('--abandoner', default=None)
+    parser.add_argument('--abandoner-username', default=None)
     parser.add_argument('--reason', default=None)
     # change-merged
     parser.add_argument('--submitter', default=None)
+    parser.add_argument('--submitter-username', default=None)
     parser.add_argument('--newrev', default=None)
     # patchset-created
     parser.add_argument('--uploader', default=None)
+    parser.add_argument('--uploader-username', default=None)
     parser.add_argument('--patchset', default=None)
-    parser.add_argument('--is-draft', default=None)
     parser.add_argument('--kind', default=None)
 
     args = parser.parse_args()