Introduce improved test logging.

build.gradle

@@ -27,6 +27,8 @@ dependencies {
     testCompile group: 'info.cukes', name: 'cucumber-junit', version: '1.1.1'
 }
 
+test.testLogging.exceptionFormat = 'full'
+
 task wrapper(type: Wrapper) {
     gradleVersion = '1.3'
 }