Make sure _url options accept only valid URL

... using the common validation template from oslo.config .

Note that this changes the format of prometheus_service_url option, but
this option has had no effect so far so the change may not affect users
really.

Change-Id: Idb73531dd50ce5dd29436831f6d1fbf34d54353b
Signed-off-by: Takashi Kajinami <kajinamit@oss.nttdata.com>
diff --git a/telemetry_tempest_plugin/config.py b/telemetry_tempest_plugin/config.py
index bf546ee..0086525 100644
--- a/telemetry_tempest_plugin/config.py
+++ b/telemetry_tempest_plugin/config.py
@@ -80,11 +80,11 @@
                 default=False,
                 help="Disable SSL certificate validation when running "
                      "scenario tests"),
-    cfg.StrOpt('sg_core_service_url',
+    cfg.URIOpt('sg_core_service_url',
                default="http://127.0.0.1:3000",
                help="URL to sg-core prometheus endpoint"),
-    cfg.StrOpt('prometheus_service_url',
-               default="127.0.0.1:9090",
+    cfg.URIOpt('prometheus_service_url',
+               default="http://127.0.0.1:9090",
                help="URL to prometheus endpoint"),
     cfg.IntOpt('ceilometer_polling_interval',
                default=300,