Expose binding of an assertj-core dependency automatically to all "touched" test tasks

[Nava2]

Associating the AssertJ dependency is done via the test configuration, i.e:

dependencies {                
    // https://mvnrepository.com/artifact/org.assertj/assertj-core
    testCompile group: 'org.assertj', name: 'assertj-core', version: '3.8.0'
}

It would be great to be able to assign this once and have it assigned to all targets that have generated sources. Probably via a "global scope" property or via the assertJ configuration.

[Nava2]

Alternately, have a check in the plugin that tries to verify that the assertJ dependency is satisfied. We shouldn't be installing it by default.