Support generate-sources/generate-test-sources phase

[egelke]

Plugins that generate (test) code don't seem to be implemented, when adding the following plugin:

               <plugin>
                    <groupId>org.assertj</groupId>
                    <artifactId>assertj-assertions-generator-maven-plugin</artifactId>
                    <version>2.2.0</version>
                    <executions>
                        <execution>
                            <id>generate</id>
                            <phase>generate-test-sources</phase>
                            <goals>
                                <goal>generate-assertions</goal>
                            </goals>
                        </execution>
                    </executions>
                </plugin>

I get the following error:

Plugin execution not covered by lifecycle configuration: org.assertj:assertj-assertions-generator-maven-plugin:2.2.0:generate-assertions (execution: generate, phase: generate-test-sources)

[Eskibear]

please open this issue in this repo: https://github.com/redhat-developer/vscode-java