Comma placement in 3.6 and 3.7 **kwargs

fixes #208

test/simple_source/bug36/07_kwargs.py

@@ -0,0 +1,9 @@
+# Bug in Python 3.6 and 3.7 was getting comma before **kw
+
+def fn(arg, *, kwarg='test', **kw):
+    assert arg == 1
+    assert kwarg == 'testing'
+    assert kw['foo'] == 'bar'
+
+
+fn(1, kwarg='testing', foo='bar')

uncompyle6/semantics/make_function.py

@@ -735,7 +735,7 @@ def make_function3(self, node, is_lambda, nested=1, code_node=None):
                     self.write(sep)
                     self.write("%s=%s" % (n, defaults[i]))
                     sep = ', '
-                    ends_in_comma = True
+                    ends_in_comma = False
                     pass
                 pass
         pass