* Added the default file locations which are based on environment variables  to `YarnClasspathProvider`
  * Added a check to make sure we work on old YARN installations
  * deprecated addClasspath() as it is unsafe in the future
  * Added means to create a single jar that contains all tests and their dependencies
  * Made `YarnClasspathProvider`  more robust against old YARN versions and misconfigured YARN installs
Local runtime uses symbolic links for jars in driver and evaluators
Merge pull request #980 from Microsoft-CISL/tmajest_symboliclinks_local_runtime

Local runtime uses symbolic links for jars in driver and evaluators.

Confirmed that this falls back cleanly to copies when links aren't supported.
  * Made sure that only relevant classes are copied to the Driver.
Merge branch 'master' of https://github.com/Microsoft-CISL/REEF into weimer_classpath_cleanups