Upgrade maven-shade-plugin to 3.2.1 to get past failure in release (#117)

Co-authored-by: Raunaq Morarka <raunaqm@qubole.com>

Author: raunaqmorarka

pom.xml

@@ -187,7 +187,7 @@
                     <plugin>
                         <groupId>org.apache.maven.plugins</groupId>
                         <artifactId>maven-shade-plugin</artifactId>
-                        <version>2.3</version>
+                        <version>3.2.1</version>
                         <configuration>
                             <createDependencyReducedPom>false</createDependencyReducedPom>
                             <filters>