Delete working copy of repository created by release plugin (#289)

* Delete working copy of repository created by release plugin

Use the maven-antrun-plugin to delete the target/checkout
directory, which is the default working copy directory
created by the Maven Release Plugin.

Closes #288

pom.xml

@@ -430,21 +430,28 @@
                         These duplicate classes will be seen by IDEs and cause problems.
                         The following ensures we delete the delomboked sources once we
                         no longer need them after generating the javadoc.
+
+                        Also remove the working copy of the repository created by
+                        the Maven Release Plugin.
                     -->
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-antrun-plugin</artifactId>
                         <version>${maven-antrun-plugin.version}</version>
                         <executions>
                             <execution>
-                                <id>delete-delombok-generated-sources</id>
+                                <id>delete-unwanted-directories</id>
                                 <phase>verify</phase>  <!-- ensure this executes after javadoc -->
                                 <goals>
                                     <goal>run</goal>
                                 </goals>
                                 <configuration>
                                     <target>
+                                        <!-- Delete the delomboked sources directory -->
                                         <delete dir="${project.build.directory}/generated-sources/delombok" />
+
+                                        <!-- Delete the checkout directory created during the release process -->
+                                        <delete dir="${project.build.directory}/checkout"/>
                                     </target>
                                 </configuration>
                             </execution>