Set PYTHONIOENCODING='utf-8' so that unicode tests can pass on CPython on

systems where another encoding is set in the locale

tests/run-tests

@@ -17,6 +17,9 @@ else:
     CPYTHON3 = os.getenv('MICROPY_CPYTHON3', 'python3')
     MICROPYTHON = os.getenv('MICROPY_MICROPYTHON', '../unix/micropython')
 
+# Set PYTHONIOENCODING so that CPython will use utf-8 on systems which set another encoding in the locale
+os.environ['PYTHONIOENCODING']='utf-8'
+
 def rm_f(fname):
     if os.path.exists(fname):
         os.remove(fname)