Add checkstyle to pom.xml

4 jobs for master in 4 minutes and 33 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #265416
build

00:00:07

 
  Test
passed #265417
test

00:00:11

 
  Deploy
passed #265418
gitlab-deploy

00:00:22

passed #265419
heroku-deploy

00:03:52