Initial Commit
Move checkstyle to subdirectory
iZettle POM v1.1

Upgrades plugin versions in izettle pom

- Bump version to v1.1

- Changed release:prepare/perform tagging to just artifactId-version

  e.g.: `izettle-example-1.0.25` This is the default and it is how other
  projects are currently being tagged

- Change release plugin to push changes

- Removed invalid javadoc option -Ddoclint:none
basepom: add checkstyle plugin, version upgrades