Add code that lets you use the GoER REST API

This is done because you are not able to get UUID:s for missing events
when you are using the GraphQl API.

This change consist of an abstration of EiffelGraphQlClient to
EiffelClient. This class includes an instance of EiffelGraphQlClient and
the new EiffelGoRestClient. GraphQlApiConfig is also renamed to
EiffelRepoApiConfig and now includes urls to both the GraphQL API and
the GoER REST API.

Solves: Jira GER-1545
Change-Id: I15467cf21180094c31c147ebcbc9c8f2be0b75c3
7 files changed
tree: 19b5d9d90815c77605319ea179dfbc9abfa602b9
  1. src/
  2. BUILD
  3. external_plugin_deps.bzl