Removed checkstyle, using IDEA default code format.

build.gradle

@@ -1,6 +1,5 @@
 plugins {
     id 'application'
-    id 'checkstyle'
     id 'com.github.ben-manes.versions' version '0.39.0'
     id 'idea'
     id 'io.gitlab.arturbosch.detekt' version '1.17.1'
@@ -153,27 +152,19 @@ jacoco {
 }
 
 jacocoTestReport {
-    dependsOn(test)
+    dependsOn test
     reports {
-        html.enabled = true
-        xml.enabled = true
-    }
-}
-
-tasks.withType(Checkstyle) {
-    reports {
-        xml.enabled = false
-        html.enabled = true
+        html.required = true
+        xml.required = true
     }
 }
 
 tasks.sonarqube {
-    dependsOn('jacocoTestReport')
+    dependsOn 'jacocoTestReport'
 }
 
 task copyToDeploy(type: Copy) {
-    from('properties')
-    from jar
+    from('properties', jar)
     into deployDir
 }