Gradle plugin proof-of-concept

[tom-seqera]

No description provided.

[bentsherman]

Just tested this with nf-prov and it works wonderfully. So much simpler 😄

Some notes:

• I would make the assemble rule first in the Makefile so that you can just run make to build the plugin

• I happen to have nf-prov cloned as a different name (nextflow-io_nf-prov), and make install used that name when installing the plugin. Setting rootProject.name to nf-prov in settings.gradle fixed this, so I would do this in nf-hello as well

• I initially moved my source files to src/main/nextflow/... instead of src/main/groovy/nextflow/.... The plugin built and installed successfully, but then Nextflow failed at runtime with a ClassNotFound exception.

  It sounds like the plugin build didn't pick up any classes, so I'm surprised it still succeeded. Since we specify the className in the build.gradle, maybe it can confirm that at least this class was picked up?