log reserved resources

On non-debug log level, show something like this at the beginning of
each suite:

 03:45:49.439720 tst handover:sysmo+secondbts-trx-b200: RESERVED RESOURCES for handover:
 bts
   sysmoBTS 1002
   Ettus B200
 ip_address
   10.42.42.2
   10.42.42.3
   10.42.42.4
   10.42.42.5
   10.42.42.6
   10.42.42.7
 modem
   sierra_1st
   sierra_2nd

Change-Id: Ic23556eafee654c93d13c5ef405028da09bd51d7
diff --git a/src/osmo_gsm_tester/core/suite.py b/src/osmo_gsm_tester/core/suite.py
index 3860d19..3e9ecbf 100644
--- a/src/osmo_gsm_tester/core/suite.py
+++ b/src/osmo_gsm_tester/core/suite.py
@@ -160,6 +160,8 @@
             raise RuntimeError('Attempt to reserve resources twice for a SuiteRun')
         self.log('reserving resources in', self.resources_pool.state_dir, '...')
         self.reserved_resources = self.resources_pool.reserve(self, self.resource_requirements(), self.resource_modifiers())
+        # short summary of labels
+        self.log('RESERVED RESOURCES for ' + self.suite_name() + ':\n' + self.reserved_resources.summary_str())
 
     def get_reserved_resource(self, resource_class_str, specifics):
         return self.reserved_resources.get(resource_class_str, specifics=specifics)