Add detailed testing log for Travis-ci

Author: jusoto

build.gradle

@@ -68,4 +68,11 @@ dependencyManagement {
 checkstyle {
     toolVersion = "8.7"
     configFile = new File(rootDir, "checkstyle.xml")
+}
+
+test {
+    testLogging {
+        events "failed"
+        exceptionFormat "full"
+    }
 }