fix: pom.xml to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-JAVA-ORGAPACHEHADOOP-30627

pom.xml

@@ -94,7 +94,7 @@ under the License.
 	<properties>
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
-		<hadoop.version>2.4.1</hadoop.version>
+		<hadoop.version>2.6.5</hadoop.version>
 		<!-- Need to use a user property here because the surefire
 			 forkCount is not exposed as a property. With this we can set
 			 it on the "mvn" commandline in travis. -->
@@ -1145,8 +1145,7 @@ under the License.
 									<stylesheet>plain.xsl</stylesheet>
 
 									<fileMappers>
-										<fileMapper
-											implementation="org.codehaus.plexus.components.io.filemappers.FileExtensionMapper">
+										<fileMapper implementation="org.codehaus.plexus.components.io.filemappers.FileExtensionMapper">
 											<targetExtension>.html</targetExtension>
 										</fileMapper>
 									</fileMappers>
@@ -1363,7 +1362,7 @@ under the License.
 						<license implementation="org.apache.rat.analysis.license.SimplePatternBasedLicense">
 							<licenseFamilyCategory>AL2 </licenseFamilyCategory>
 							<licenseFamilyName>Apache License 2.0</licenseFamilyName>
-							<notes />
+							<notes/>
 							<patterns>
 								<pattern>Licensed to the Apache Software Foundation (ASF) under one</pattern>
 							</patterns>
@@ -1901,7 +1900,7 @@ under the License.
 								<order>org.apache.flink,org.apache.flink.shaded,,javax,java,scala,\#</order>
 							</importOrder>
 
-							<removeUnusedImports />
+							<removeUnusedImports/>
 						</java>
 					</configuration>
 					<executions>