Fix: Turn warning into an error when warning flag is set to 'error'

This functionality can be used to change warnings into errors that can
be detected in transformation error tests. See 'vlan-trunk-l3-attr'
test for an example.

Author: ipspace

netsim/utils/log.py

@@ -316,6 +316,8 @@ def warning(*,
   if flag_value is False:
     return
 
+  if flag_value == 'error':
+    kwargs['category'] = ErrorAbort
   if 'category' not in kwargs:
     kwargs['category'] = Warning