Bump spotless-maven-plugin from 2.21.0 to 2.22.0 (#151)

pom.xml

@@ -139,7 +139,7 @@
       <plugin>
         <groupId>com.diffplug.spotless</groupId>
         <artifactId>spotless-maven-plugin</artifactId>
-        <version>2.21.0</version>
+        <version>2.22.0</version>
         <configuration>
           <java>
             <importOrder/>