Merge pull request #1006 from square/renovate/org.apache.maven.plugins-maven-checkstyle-plugin-3.x

Update dependency org.apache.maven.plugins:maven-checkstyle-plugin to v3.4.0

Author: JakeWharton

pom.xml

@@ -118,7 +118,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-checkstyle-plugin</artifactId>
-        <version>3.3.1</version>
+        <version>3.4.0</version>
         <dependencies>
           <dependency>
             <groupId>com.puppycrawl.tools</groupId>