Upgraded Storm dependency to 0.9.3

This commit upgrades the Storm dependency to the latest release, 0.9.3.

The Storm 0.9.3 release included dependency deconfliction measures that
shaded Google Guava (among others). Rather than adding Google Guava as
a maven dependency, we’re making use of the storm-packaged version
(packages and classes are imported from org.apache.storm.guava instead
of com.google.common).