set utf-8 for python env test

Author: jurgen-lentz

amplpy/tests/test_environment.py

@@ -23,6 +23,8 @@ def test_environment_initialization(self):
     def test_environment(self):
         from amplpy import Environment, AMPL
 
+        os.environ["PYTHONIOENCODING"] = "utf-8"
+
         env1 = Environment()
         env2 = Environment(os.curdir)
         self.assertEqual(env2.get_bin_dir(), os.curdir)