Noxfile adjustment, simple test

noxfile.py

@@ -1,11 +1,12 @@
 import nox
 
+@nox.session
+def lint(session):
+    session.install('ruff')
+    session.run('ruff', 'check', '--exclude', 'examples')
+
 @nox.session
 def tests(session):
     session.install('pytest')
     session.run('pytest')
 
-def lint(session):
-    session.install('flake8')
-    session.run('flake8', '--import-order-style', 'google')
-

tests/test_datatype.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python3
+import unittest
+
+import pyFroniusReg.froniusreg as froniusreg
+
+class TestDataTypes(unittest.testCase):
+
+    def test_int16(self):
+        assert froniusreg.int16.decode(froniusreg.int16.encode(65536)) == 65535
+
+
+if __name__ == '__main__':
+    unittest.main()
+