Add log4j properties

Summary:
Without having this in here log4j isn't initialized properly.
Having this in allows for the generated messages to be properly printed

Test Plan: java -cp spragger.jar com.scaledata.spragger.swagger.spray.SprayGenerator

Reviewers: prateek.pandey, soham, nitro, kt

Reviewed By: kt

Subscribers: eng

Differential Revision: http://phabricator.scale-data.com/D1172