Add spotless configuration

Add a basic Spotless configuration that takes care of:

 * the license header in Java, XML and YAML files,
 * whitespace in Java and POM files,
 * import order in Java files,
 * unused imports in Java files,
 * ordering of main POM elements.
3 files changed
tree: 48d31c98cf820c508616da457066e0bd1f8cfe2d
  1. .github/
  2. .gitignore
  3. pom.xml