Add enforcer for the version tag in CHANGELOG.md.

pom.xml

@@ -924,6 +924,33 @@
 				</executions>
 			</plugin>
 
+			<plugin>
+				<groupId>org.codehaus.gmaven</groupId>
+				<artifactId>groovy-maven-plugin</artifactId>
+				<version>2.0</version>
+				<executions>
+					<execution>
+						<phase>process-classes</phase>
+						<goals>
+							<goal>execute</goal>
+						</goals>
+						<configuration>
+							<defaults>
+								<name>tag</name>
+							</defaults>
+							<source>
+								def fileContents = new File("${project.basedir}/CHANGELOG.md").getText('UTF-8')
+								matcher = (fileContents =~ /(?s).\[v$project.version\].*?/)
+								if (!matcher.find()) {
+									throw new IllegalArgumentException("Tag [v$project.version] not found in CHANGELOG.md")
+								}
+								assert matcher[0][1]:  "Tag [v$project.version] not found in CHANGELOG.md"
+							</source>
+						</configuration>
+					</execution>
+				</executions>
+			</plugin>
+
 		</plugins>
 	</build>