Readd tests

test/contracts/test.aes

@@ -1,5 +1,12 @@
 // This is a custom test file if you need to run a compiler without
 // changing aeso_compiler_tests.erl
 
-contract C =
-  entrypoint test() = [1..5]
+include "List.aes"
+
+contract IntegerHolder =
+  type state = int
+  entrypoint init(x) = x
+  entrypoint get() = state
+
+main contract Test =
+  stateful entrypoint f(c) = Chain.clone(ref=c, 123)