[autotest] add a --ssh_options option to autoserv

This CL follows the template of
https://chromium-review.googlesource.com/167415

BUG=chromium:285378
TEST=Unit tests pass. Manually verified that specifying
--ssh_options="-F /dev/null -i /dev/null" caused those flags to be
threaded into ssh commands.

Change-Id: Ie0496862d05d42192d55501fc0ed1c3a6274fe79
Reviewed-on: https://chromium-review.googlesource.com/168099
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
diff --git a/server/autoserv b/server/autoserv
index 95d6c3d..b3b3bb4 100755
--- a/server/autoserv
+++ b/server/autoserv
@@ -105,6 +105,7 @@
     verify_job_repo_url = parser.options.verify_job_repo_url
     skip_crash_collection = parser.options.skip_crash_collection
     ssh_verbosity = int(parser.options.ssh_verbosity)
+    ssh_options = parser.options.ssh_options
 
     # can't be both a client and a server side test
     if client and server:
@@ -158,7 +159,8 @@
     job = server_job.server_job(control, parser.args[1:], results, label,
                                 user, machines, client, parse_job,
                                 ssh_user, ssh_port, ssh_pass,
-                                ssh_verbosity_flag, test_retry, **kwargs)
+                                ssh_verbosity_flag, ssh_options,
+                                test_retry, **kwargs)
     job.logging.start_logging()
     job.init_parser()