add smoke tests

tests/black/test1.newt

@@ -0,0 +1,9 @@
+module Scratch
+
+nat : U
+nat = {C : U} -> C -> (nat -> C) -> C
+
+-- TESTCASE This was broken when I wasn't expanding Ref ty in check
+-- Also broken when I tried to put Def in VRef
+succ : nat -> nat
+succ = \n => \ z s => s n