Add API route to update TAF common packages

[colinpmillar]

Summary

Allow admins to update R packages via an API route such as:

http://taf.ices.local/rpackages/update

will require authentication with user required to be an admin

Tasks required

• [ ] code up logic in new controller: RPackagesController
• [ ] code up implementation as a new service: RPackagesService
• [ ] test

Links to other issues?