If you would like to contribute to the development of OpenStack, you must follow the steps documented at:
http://docs.openstack.org/developer/horizon/contributing.html
or https://wiki.openstack.org/wiki/How_To_Contribute#If_you.27re_a_developer
Once those steps have been completed, changes to OpenStack should be submitted for review via the Gerrit tool, following the workflow documented at:
https://wiki.openstack.org/GerritWorkflow
Pull requests submitted through GitHub will be ignored.
Bugs should be filed on Launchpad, not GitHub:
https://bugs.launchpad.net/horizon