Improve Spring Boot based samples

Fixes gh-693

samples/boot/redis/src/main/java/sample/config/WebMvcConfig.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2014-2017 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 sample.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+
+@Configuration
+public class WebMvcConfig extends WebMvcConfigurerAdapter {
+
+	@Override
+	public void addViewControllers(ViewControllerRegistry registry) {
+		registry.addViewController("/").setViewName("index");
+	}
+
+}