NIFI-8778: update maven requirements

Signed-off-by: Matthew Burgess <mattyb149@apache.org>

This closes #5214
diff --git a/README.md b/README.md
index d6d3e1e..430e2c4 100644
--- a/README.md
+++ b/README.md
@@ -61,7 +61,7 @@
 
 ## Requirements
 * JDK 1.8 (*ongoing work to enable NiFi to run on Java 9/10/11; see [NIFI-5174](https://issues.apache.org/jira/browse/NIFI-5174)*)
-* Apache Maven 3.1.1 or newer
+* Apache Maven 3.6.0 or newer
 * Git Client (used during build process by 'bower' plugin)
 
 ## Getting Started
diff --git a/pom.xml b/pom.xml
index d68a1a4..5872e95 100644
--- a/pom.xml
+++ b/pom.xml
@@ -614,7 +614,7 @@
                                 </requireSameVersions>
                                 <requireMavenVersion>
                                     <!-- We do not test this value so we should probably make it something fairly recent -->
-                                    <version>3.1.1</version>
+                                    <version>3.6.0</version>
                                 </requireMavenVersion>
                             </rules>
                         </configuration>