Change the following to replace Python 2 code with Python 3:

1) Replace the deprecated unit test method.
2) Wraps filter usage in a list call.
3) Converts the old metaclass syntax to new.
4) Use range instead of xrange method.
5) Change Unicode to str.
6) Several other transformations.
7) Fixed change password test cases.
8) Use simplejson instead of plain JSON.

web/pgAdmin4.py

@@ -81,7 +81,7 @@ config.SETTINGS_SCHEMA_VERSION = SCHEMA_VERSION
 if not os.path.isfile(config.SQLITE_PATH):
     setup_py = os.path.join(
         os.path.dirname(os.path.realpath(u_encode(__file__, fs_encoding))),
-        u'setup.py'
+        'setup.py'
     )
     exec(open(file_quote(setup_py), 'r').read())