Simplify Gradle example (cucumber#1394)

[Examples] Simplify Gradle example

Author: pkubowicz

examples/java-gradle/README.md

@@ -28,11 +28,10 @@ If you're writing your step definitions in Java then the Gradle script needs to
 
 Here are some caveats:
 
- * The `cucumber` task has to depend on `compileTestJava` task in order to compile test sources
+ * The `cucumber` task has to depend on `testClasses` task in order to compile test sources
 
  ```groovy
- task cucumber() {
-     dependsOn assemble, compileTestJava
+ task cucumber(dependsOn: testClasses) {
      ...
  }
  ```
@@ -41,7 +40,7 @@ Here are some caveats:
  Otherwise Cucumber-JVM will not find your production classes/resources and step definitions respectively.
 
  ```groovy
- classpath = configurations.cucumberRuntime + sourceSets.main.output + sourceSets.test.output
+ classpath = configurations.testRuntimeClasspath + sourceSets.main.output + sourceSets.test.output
  ```
 
  * Cucumber's `--glue` should be set to your package name (e.g. `gradle.cucumber`) and **NOT** to `src/test/java`

examples/java-gradle/build.gradle

@@ -1,17 +1,10 @@
 apply plugin: 'java'
 
-configurations {
-    cucumberRuntime {
-        extendsFrom testRuntime
-    }
-}
-
-task cucumber() {
-    dependsOn assemble, compileTestJava
+task cucumber(dependsOn: testClasses) {
     doLast {
         javaexec {
             main = "cucumber.api.cli.Main"
-            classpath = configurations.cucumberRuntime + sourceSets.main.output + sourceSets.test.output
+            classpath = configurations.testRuntimeClasspath + sourceSets.main.output + sourceSets.test.output
             args = ['--plugin', 'pretty', '--glue', 'gradle.cucumber', 'src/test/resources']
         }
     }