Upgrade to Spring Boot 2.6.1 and fix Maven build

Author: Dave Syer

pom.xml

@@ -5,12 +5,12 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>org.springframework.samples</groupId>
   <artifactId>spring-petclinic</artifactId>
-  <version>2.5.0-SNAPSHOT</version>
+  <version>2.6.0-SNAPSHOT</version>
 
   <parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
-    <version>2.5.6</version>
+    <version>2.6.1</version>
   </parent>
   <name>petclinic</name>
 

src/checkstyle/nohttp-checkstyle-suppressions.xml

@@ -5,6 +5,7 @@
 <suppressions>
 	<suppress files="node_modules/.*" checks=".*"/>
 	<suppress files="node/.*" checks=".*"/>
+	<suppress files="build/.*" checks=".*"/>
 	<suppress files="[\\/]build.log" checks="NoHttp"/>
 	<suppress files=".+\.(jar|git|ico|p12|gif|jks|jpg|svg)" checks="NoHttp"/>
 </suppressions>