Require minimal versions of Maven and Java

Author: egonw

pom.xml

@@ -186,6 +186,29 @@
 							</execution>
 						</executions>
 					</plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-enforcer-plugin</artifactId>
+                <version>3.5.0</version>
+                <executions>
+                    <execution>
+                        <id>enforce-maven</id>
+                        <goals>
+                            <goal>enforce</goal>
+                        </goals>
+                        <configuration>
+                            <rules>
+                                <requireMavenVersion>
+                                    <version>3.6.3</version>
+                                </requireMavenVersion>
+                                <requireJavaVersion>
+                                    <version>11</version>
+                                </requireJavaVersion>
+                            </rules>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
 				</plugins>
                         </build>