Deprecated a few methods:

  * `TangUtils` should be provided by Tang, not REEF
  * `EnvironmentUtils.addAll()` should be provided by Tang
  * `EnvironmentUtils.getReefHome()` makes no sense any more, given that REEF isn't assumed to be "installed"
  * `EnvironmentUtils.getClassLocationFile()` was never used and is merely a shorthand for JDK functionality.
 * Deprecated `EnvironmentUtils.getVersion()` in favor of `REEF.getVersion()`
Merge pull request #726 from Microsoft-CISL/weimer_deprecations

Deprecated a few methods