HADOOP-19269. Upgrade maven-shade-plugin 3.6.0 (#7029)

Contributed by PJ Fanning

hadoop-project/pom.xml

@@ -176,7 +176,7 @@
     <maven-clean-plugin.version>3.1.0</maven-clean-plugin.version>
     <maven-install-plugin.version>2.5.1</maven-install-plugin.version>
     <maven-resources-plugin.version>2.6</maven-resources-plugin.version>
-    <maven-shade-plugin.version>3.4.1</maven-shade-plugin.version>
+    <maven-shade-plugin.version>3.6.0</maven-shade-plugin.version>
     <maven-jar-plugin.version>2.5</maven-jar-plugin.version>
     <maven-war-plugin.version>3.1.0</maven-war-plugin.version>
     <maven-source-plugin.version>2.3</maven-source-plugin.version>