Update assertj-core to 3.19.0

Issue gh-344

gradle/dependency-management.gradle

@@ -27,7 +27,7 @@ dependencyManagement {
 	dependencies {
 		dependency "javax.servlet:javax.servlet-api:4.0.1"
 		dependency 'junit:junit:4.13.2'
-		dependency 'org.assertj:assertj-core:3.18.1'
+		dependency 'org.assertj:assertj-core:3.19.0'
 		dependency 'org.mockito:mockito-core:3.6.28'
 		dependency "com.squareup.okhttp3:mockwebserver:3.14.9"
 		dependency "com.squareup.okhttp3:okhttp:3.14.9"