add swagger-API and example controller

src/main/java/mops/gruppen2/Gruppen2Application.java

@@ -2,10 +2,22 @@ package mops.gruppen2;
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import springfox.documentation.builders.RequestHandlerSelectors;
+import springfox.documentation.spi.DocumentationType;
+import springfox.documentation.spring.web.plugins.Docket;
+import springfox.documentation.swagger2.annotations.EnableSwagger2;
 
 @SpringBootApplication
+@EnableSwagger2
 public class Gruppen2Application {
     public static void main(String[] args) {
         SpringApplication.run(Gruppen2Application.class, args);
     }
+
+    @Bean
+    public Docket productAPI(){
+        return new Docket(DocumentationType.SWAGGER_2).select()
+                .apis(RequestHandlerSelectors.basePackage("mops.gruppen2")).build();
+    }
 }