If you would like to contribute to the development of oslo’s libraries, first you must take a look to this page:
If you would like to contribute to the development of OpenStack, you must follow the steps in this page: http://docs.openstack.org/infra/manual/developers.html
Once those steps have been completed, changes to OpenStack should be submitted for review via the Gerrit tool, following the workflow documented at: http://docs.openstack.org/infra/manual/developers.html#development-workflow
Pull requests submitted through GitHub will be ignored.
Bugs should be filed on Launchpad, not GitHub: https://bugs.launchpad.net/oslo.serialization