Introduce ip.access nanobts support

Change-Id: Ibaea025b3a503dfe897d36701234445de6d49f82
diff --git a/src/osmo_gsm_tester/suite.py b/src/osmo_gsm_tester/suite.py
index e7c68b7..106994e 100644
--- a/src/osmo_gsm_tester/suite.py
+++ b/src/osmo_gsm_tester/suite.py
@@ -212,6 +212,11 @@
         while self._processes:
             self._processes.pop().terminate()
 
+    def stop_process(self, process):
+        'Remove process from monitored list and stop it'
+        self._processes.remove(process)
+        process.terminate()
+
     def free_resources(self):
         if self.reserved_resources is None:
             return