Dial with potentially empty test description in LitTestCommand.
diff --git a/zorg/buildbot/commands/LitTestCommand.py b/zorg/buildbot/commands/LitTestCommand.py
index 3b34777..bd029a8 100644
--- a/zorg/buildbot/commands/LitTestCommand.py
+++ b/zorg/buildbot/commands/LitTestCommand.py
@@ -179,7 +179,7 @@
     return SUCCESS
 
   def describe(self, done=False):
-    description = Test.describe(self, done)
+    description = Test.describe(self, done) or list()
     for name, count in self.logObserver.resultCounts.items():
         if name in self.resultNames:
             description.append('{0} {1}'.format(count, self.resultNames[name]))