FIX: Add infrastructure for python tests (#91)

Also integrated with CI and runs tests in documentation

bindings/python/tests/test_create.py

@@ -0,0 +1,8 @@
+import ironcalc as ic
+
+def test_simple():
+    model = ic.create("model", "en", "UTC")
+    model.set_user_input(0, 1, 1, "=1+2")
+    model.evaluate()
+
+    assert model.get_formatted_cell_value(0, 1, 1) == "3"