Add owa to addon index

[patrick (Patrick Luboobi)]

Hello, could someone help me review and merge this PR as it is key to the release of addon manager: PR: https://github.com/openmrs/openmrs-contrib-addonindex/pull/39

project repo: https://github.com/openmrs/openmrs-owa-addonmanager

[dkayiwa (Daniel Kayiwa)]

Just merged.