wta: Run only one sample when bisecting

This divides the time to bisect by five.

wta/bench.py

@@ -234,6 +234,8 @@ def find_bad(args, good):
 def bisect_states(args):
     check_zerotrans(args)
 
+    samples = 1
+
     states = args.start_states
 
     good = args.good or 0
@@ -290,6 +292,8 @@ def bisect_trans(args):
 
     transitions = args.start_transitions
 
+    samples = 1
+
     good = args.good or 0
     bad = args.bad