Build an rpm to deploy appointments-frontend code in the bahmni instance

[buvaneswari-arun]

As part of the card, we have to create an rpm which will package the appointments-frontend code. And this is used to deploy the appointments-frontend code on the bahmni instance so that i will be able to access the appointments from bahmni UI.

For reference, please check the implementer-ineterface build.gradle file
https://github.com/Bahmni/implementer-interface/blob/master/package/build.gradle