Add maven enforcer plugin

[farodin91]

Example from JanusGraph/pom.xml

<plugin>        
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-enforcer-plugin</artifactId>
    <version>3.0.0-M2</version>
    <executions>
        <execution>
            <id>enforce-dependency-convergence</id>
            <goals>
                <goal>enforce</goal>
            </goals>
            <configuration>
                <rules>
                    <requireUpperBoundDeps>
                        <excludes>
                            <exclude>com.google.guava:guava</exclude>
                        </excludes>
                    </requireUpperBoundDeps>
                    <DependencyConvergence />
                </rules>
            </configuration>
        </execution>
    </executions>
</plugin>