Allow for new plugin mechanism

[ambition-consulting]

As stated here, since gradle 2.1 a new plugin mechanism (using "id") should be supported. When applied, I get various errors on URI schemes not being supported though. Only using the legacy plugin mechanism (with buildscript and apply plugin) will result in correct behaviour.

[ysb33r]

Indeed. The problem is described on the Gradle Forum: https://discuss.gradle.org/t/plugins-block-does-not-handle-classpath-correctly-under-certain-circumstances/18222/9.

IIRC it was fixed in the Gradle 3.0 release.

[ambition-consulting]

I am currently using gradle 2.12. When I switch to gradle 3.0, I will double check if it works. If so, a short hint in the README might help?