cli.cmdoptions: Add 'use_keyring' flag, defaulting to False

Author: nicoonoclaste

src/pip/_internal/cli/cmdoptions.py

@@ -766,6 +766,15 @@ def _handle_no_use_pep517(option, opt, value, parser):
     help=SUPPRESS_HELP
 )  # type: Any
 
+use_keyring = partial(
+    Option,
+    '--use-keyring',
+    dest='use_keyring',
+    action='store_true',
+    default=False,
+    help="Attempt to get credentials from the user's keyring."
+)  # type: Any
+
 install_options = partial(
     Option,
     '--install-option',