Update CheckstyleMavenPlugin to 3.0.0 and Checkstyle to 8.19

Author: Stephen Powis

pom.xml

@@ -60,8 +60,8 @@
 
         <!-- Specify which Checkstyle ruleset to use -->
         <checkstyle.ruleset>build/checkstyle-v1.5.xml</checkstyle.ruleset>
-        <checkstyle.plugin.version>2.17</checkstyle.plugin.version>
-        <checkstyle.version>8.17</checkstyle.version>
+        <checkstyle.plugin.version>3.0.0</checkstyle.plugin.version>
+        <checkstyle.version>8.19</checkstyle.version>
 
         <!-- Log4J Version -->
         <log4j2.version>2.11.1</log4j2.version>
@@ -212,7 +212,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-checkstyle-plugin</artifactId>
-                <version>2.17</version>
+                <version>${checkstyle.plugin.version}</version>
                 <executions>
                     <execution>
                         <id>checkstyle-validate</id>