Move Joshua to the Attic

1. Confirm Board Resolution
2. Inform users of the move to the Attic
3. Create project page on Attic site: http://attic.apache.org/projects/joshua
4. Ensure original project site pages carry the Attic banner
5. Update the project DOAP file (if any) or copy to projects-override:
6. Announce on announce at apache.org

See http://attic.apache.org/process.html#howto for detailed instructions

Open an Infrastructure JIRA issue identifying the resources that need turning off/making read only => INFRA-22583