Document tests.

documentation/index.html

@@ -589,7 +589,43 @@ New versions found:
   </tr>
 </table>
 
+<h2 class="section" id="testing">Testing</h2>
+<p>
+  Kobalt automatically detects how to run your tests based on the test dependencies that you declared:
+</p>
+<pre class="brush:java">
+dependenciesTest {
+    compile("org.testng:testng:6.9.9")
+}</pre>
+<p>
+  By default, Kobalt supports TestNG, JUnit and Spek. You can also configure how your tests run
+  with the <code>test{}</code> directive:
+</p>
+<pre class="brush:java">
+test {
+    args("-excludegroups", "broken", "src/test/resources/testng.xml")
+}</pre>
+<p>
+    The full list of configuration parameters can be found in the <a href="https://github.com/cbeust/kobalt/blob/master/modules/kobalt-plugin-api/src/main/kotlin/com/beust/kobalt/TestDirective.kt#L6">TestConfig</a> class.
+</p>
+<p>
+  Additionally, you can define multiple test configurations, each with a different name. Each
+  configuration will create an additional task named <code>"test"</code> followed by the name of
+  that configuration. For example:
+</p>
+<pre>
+test {
+    args("-excludegroups", "broken", "src/test/resources/testng.xml")
+}
 
+test {
+    name = "All"
+    args("src/test/resources/testng.xml")
+}</pre>
+<p>
+  The first configuration has no name, so it will be launched with the task <code>"test"</code>,
+  while the second one can be run with the task <code>"testAll"</code>.
+</p>
 <h2 class="section" id="publishing">Publishing</h2>
 
 <p>