CDK-515: Added tests for Spark jobs reading from/writing to Datasets.

 * Added spark-core_2.10 under dependency management
 * Implemented tests that use FileSystemDataset and HBaseDataset
I don't think Hadoop uses asm directly, but I'm not sure why it was included. The jetty artifacts should be excluded in the artifact.hadoop-deps pom. Adding exclusions (or changing the dependencies in general) should only be done if the examples have been tested.