more demo test cases

- added them to cfg/dummy_cfg.py
+ treat enum correctly in SecopClient.setParameterFromString

Change-Id: Ia5b2d8d3a21c3215cb93d90975086eb9995b1543

frappy_demo/cryo.py

@@ -161,7 +161,7 @@ class Cryostat(CryoBase):
 
         by setting the current setpoint as new target"""
         # XXX: discussion: take setpoint or current value ???
-        self.write_target(self.setpoint)
+        self.write_target(self.setpoint if self.mode == 'ramp' else self.value)
 
     #
     # calculation helpers