Remove old and no longer used testsuites

@JavierJia @Elmira88 

This PR remove the old and no longer used pregel testsuites. 

@Elmira88 I created a RayScaffoldingTestSuite for you. It's under edu.uci.ics.genomix.pregelix.jobrun.pipeline. You can test Ray by simply adding testcase to data/TestSet/Ray_Scaffolding. This input file should be already preprocessed by graph building.