added slf4j-api to the PMD plugin dependencies to trick the MoreThanOneLoggerRule into ignoring multiple SLF4j loggers
added a @SuppressWarnings("PMD.MoreThanOneLogger") annotation to JsonEventLogger to more properly address the fact that we specifically want more than one logger.
Merge pull request #237 from adamcin/defect/parent/pmd-maven-3.0.5-compatibility

Resolved PMD Violation: MoreThanOneLogger