Add --env=uat (User Acceptance Testing)

Author: mdmintz

seleniumbase/plugins/base_plugin.py

@@ -62,6 +62,7 @@ def options(self, parser, env):
                 constants.Environment.BETA,
                 constants.Environment.MAIN,
                 constants.Environment.TEST,
+                constants.Environment.UAT,
             ),
             default=constants.Environment.TEST,
             help="""This option sets a test env from a list of choices.

seleniumbase/plugins/pytest_plugin.py

@@ -210,6 +210,7 @@ def pytest_addoption(parser):
             constants.Environment.BETA,
             constants.Environment.MAIN,
             constants.Environment.TEST,
+            constants.Environment.UAT,
         ),
         default=constants.Environment.TEST,
         help="""This option sets a test env from a list of choices.