Add reference documentation and create docs zip

Add reference documentation for the project and add a docs artifact
that contains both the reference documentation and the javadoc.

See gh-37

docs/src/test/java/com/example/InvokeService.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2014-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example;
+
+import static org.springframework.restdocs.RestDocumentation.document;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+public class InvokeService {
+
+	private MockMvc mockMvc;
+	
+	public void invokeService() throws Exception {
+		// tag::invoke-service[]
+		this.mockMvc.perform(get("/").accept(MediaType.APPLICATION_JSON)) // <1>
+			.andExpect(status().isOk()) // <2>
+			.andDo(document("index")); // <3>
+		// end::invoke-service[]
+	}
+	
+}