Add CLI app using Java Modules -- requires Java 11

[msgilligan]

Add a CLI app example using Java Modules

Use the org.javamodularity.moduleplugin Gradle plugin (which requires Java 11)

Does not work with Micronaut 1.1.0:

./gradlew clean run

> Configure project :
Found module name 'cli.app.modular.java'

> Task :compileJava FAILED
error: the unnamed module reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.configuration.picocli reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.validation reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.http reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.aop reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.core reads package javax.annotation from both java.annotation and jsr305
error: module slf4j.api reads package javax.annotation from both java.annotation and jsr305
error: module java.validation reads package javax.annotation from both java.annotation and jsr305
error: module com.fasterxml.jackson.datatype.jdk8 reads package javax.annotation from both java.annotation and jsr305
error: module com.fasterxml.jackson.datatype.jsr310 reads package javax.annotation from both java.annotation and jsr305
error: module com.fasterxml.jackson.databind reads package javax.annotation from both java.annotation and jsr305
error: module io.reactivex.rxjava2 reads package javax.annotation from both java.annotation and jsr305
error: module java.annotation reads package javax.annotation from both java.annotation and jsr305
error: module javax.inject reads package javax.annotation from both java.annotation and jsr305
error: module snakeyaml reads package javax.annotation from both java.annotation and jsr305
error: module com.fasterxml.jackson.annotation reads package javax.annotation from both java.annotation and jsr305
error: module com.fasterxml.jackson.core reads package javax.annotation from both java.annotation and jsr305
error: module org.reactivestreams reads package javax.annotation from both java.annotation and jsr305
error: module jsr305 reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.inject reads package javax.annotation from both java.annotation and jsr305
error: module info.picocli reads package javax.annotation from both java.annotation and jsr305
error: module io.micronaut.runtime reads package javax.annotation from both java.annotation and jsr305
/Users/sean/git/micronaut-examples/cli-app-modular-java/src/main/java/module-info.java:1: error: module cli.app.modular.java reads package javax.annotation from both java.annotation and jsr305
module cli.app.modular.java {
^
23 errors

[CLAassistant]

All committers have signed the CLA.

[msgilligan]

ee2b20c fixes the split package problem.

Note: There are still some conflicts between shadow plugin and
module plugin and between picocli and application plugin run task.

[benmccann]

It might be considered to remove the shadow plugin: #9