Update test suite

Put all ffi code into its own module for clarity.

test/test_movegen.py

@@ -0,0 +1,10 @@
+import ctypes
+from test.base import ChessLibTestBase
+
+
+
+
+class TestMoveGeneration(ChessLibTestBase):
+    @classmethod
+    def setUpClass(cls):
+        pass