Alfred API tests and docker unavailable for external contributors

[rschev]

External contributors cannot use the docker tasks (and the integration test tasks, which depend on the docker tasks), because the apix-docker/*/build.gradle contains several mentions of org.alfresco:alfresco-enterprise in the baseAlfrescoWar. This is only available on Alfresco's private nexus.

Even external contributors that have access to the private nexus won't be able to build it because the need for this repository isn't declared anywhere. Likely the build only works on our machines because of the global configuration in $HOME/.gradle/init.gradle.

Looking more towards the future, I'd like to see our integration tests still run on enterprise by default, but have the option of spinning up a community-based docker container easily (e.g. with a commandline flag).