Out of the box container goal definitions

[cdupuis]

We need to build up a catalogue of container goal definitions. Currently we got:

• https://github.com/atomist/maven-goal
• https://github.com/atomist/npm-goal
• https://github.com/atomist/docker-goal
• https://github.com/atomist/version-goal

We should add:

• [ ] Kaniko docker build
• [ ] Leinigen build & test
• [x] Gradle build & test
• [ ] Kubernetes deploy using our KubernetesDeploy goal

[lievendoclo]

Added Gradle goal: https://github.com/atomist/gradle-goal

[lievendoclo]

Added .NET Core: https://github.com/atomist/dotnetcore-goal

[ddgenome]

Other priorities and issues are driving the creation of the container goals/skills now.