decode (possibly) binary output streams when running kat -v or kat -h

pykat/finesse.py

@@ -2071,11 +2071,11 @@ class kat(object):
         p = Popen([self._finesse_exec(kat_binary), '-v'], stdout=PIPE, stderr=PIPE)
 
         out, err = p.communicate()
+        
+        if err:
+            raise pkex.BasePyKatException("Error getting version: " + str(err.decode("utf-8")))
 
-        if err is not None:
-            raise pkex.BasePyKatException("Error getting version: " + str(err))
-
-        vals = str(out).split()
+        vals = str(out.decode("utf-8")).split()
 
         return vals[2][1:-2] #Format: Finesse 2.2 (2.2-0-g994eac8), 03.07.2017
 
@@ -2099,8 +2099,8 @@ class kat(object):
 
         out, err = p.communicate()
 
-        if err is not None:
-            raise pkex.BasePyKatException("Error getting version: " + str(err))
+        if err:
+            raise pkex.BasePyKatException("Error getting syntax: " + str(err.decode("utf-8")))
 
         print(out.decode("utf-8"))
         return out.decode("utf-8")