THRIFT-3337 Add testBool method to cross tests

This closes #611
diff --git a/test/py/TestServer.py b/test/py/TestServer.py
index bcf9376..89b74da 100755
--- a/test/py/TestServer.py
+++ b/test/py/TestServer.py
@@ -76,6 +76,11 @@
       print 'testString(%s)' % str
     return str
 
+  def testBool(self, boolean):
+    if options.verbose > 1:
+      print 'testBool(%s)' % str(boolean).lower()
+    return boolean
+
   def testByte(self, byte):
     if options.verbose > 1:
       print 'testByte(%d)' % byte