Include spock testing support in the application

This requires pinning a specific minor version of Groovy since Spock requires a
specific package name for each major/minor release of Groovy

build.gradle

@@ -29,14 +29,11 @@ repositories {
 }
 
 dependencies {
-    compile localGroovy()
+    compile 'org.codehaus.groovy:groovy-all:[2.4.7,2.5.0)'
     compile "io.dropwizard:dropwizard-core:${dropwizardVersion}"
 
-    // Declare the dependency for your favourite test framework you want to use in your tests.
-    // TestNG is also supported by the Gradle Test task. Just change the
-    // testCompile dependency to testCompile 'org.testng:testng:6.8.1' and add
-    // 'test.useTestNG()' to your build script.
-    testCompile 'junit:junit:4.12'
+    testCompile "io.dropwizard:dropwizard-testing:${dropwizardVersion}"
+    testCompile 'org.spockframework:spock-core:1.0-groovy-2.4'
 }
 
 task generateExampleYaml {
@@ -55,3 +52,13 @@ run {
     args 'server', "${buildDir}/httpwizard.example.yml"
     dependsOn generateExampleYaml
 }
+
+test {
+    testLogging {
+        /* we want more test failure information, see:
+         *  <http://mrhaki.blogspot.com/2013/05/gradle-goodness-show-more-information.html>
+         */
+        exceptionFormat = 'full'
+        events "passed", "skipped", "failed", "standardOut", "standardError"
+    }
+}

src/test/groovy/io/lasagna/httpwizard/HttpWizardSpec.groovy

@@ -0,0 +1,14 @@
+
+package io.lasagna.httpwizard
+
+import spock.lang.Specification
+
+class HttpWizardSpec extends Specification {
+    def "ensure app can be instantiated"() {
+        when:
+        def app = new HttpWizard()
+
+        then:
+        app instanceof HttpWizard
+    }
+}