implement datatypes

+tests

as agreed in last meeting

Change-Id: Ibc382f808927797e7e7ea268b97a5632713bfb56

test/conftest.py

@@ -0,0 +1,19 @@
+# content of conftest.py
+import pytest
+
+
+@pytest.fixture(scope="module")
+def constants():
+    # setup
+    class Constants(object):
+        ONE = 1
+        TWO = 2
+    c = Constants()
+    yield c
+    # teardown
+    del c
+
+
+@pytest.fixture(scope="session")
+def globals():
+    return dict()