This is a not a great idea, because for the older versions of Hadoop this will bump the `servlet-api` dependency from 2.X to 3.X...  

It also looks like Hadoop officially advertises version 2.5 of the servlet-api for both 2.3.0 and 2.4.0:
http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-project/2.3.0/hadoop-project-2.3.0.pom
http://repo1.maven.org/maven2/org/apache/hadoop/hadoop-project/2.4.0/hadoop-project-2.4.0.pom