KNOX-2184 - Upgrade maven-enforcer-plugin to 3.0.0-M3

Signed-off-by: Kevin Risden <krisden@apache.org>
diff --git a/pom.xml b/pom.xml
index 2b04173..7bf1993 100644
--- a/pom.xml
+++ b/pom.xml
@@ -226,7 +226,7 @@
         <maven-checkstyle-plugin.version>3.1.0</maven-checkstyle-plugin.version>
         <maven-compiler-plugin.version>3.8.1</maven-compiler-plugin.version>
         <maven-dependency-plugin.version>3.1.1</maven-dependency-plugin.version>
-        <maven-enforcer-plugin.version>3.0.0-M2</maven-enforcer-plugin.version>
+        <maven-enforcer-plugin.version>3.0.0-M3</maven-enforcer-plugin.version>
         <maven-pmd-plugin.version>3.12.0</maven-pmd-plugin.version>
         <metrics.version>4.1.1</metrics.version>
         <mina.version>2.0.21</mina.version>