Tests - Include task stdout/err if exit code != 0
Merging in latest from upstream (TM/task:refs/heads/2.4.0)

* commit 'd8b7d914acca17f8b8850c057c29bb32b9703078': (31 commits)
  TW-5
  TW-306
  Code Cleanup
  Documentation
  TW-285
  Unit Tests
  Unit Tests
  Code Cleanup
  TW-115
  TW-1257
  TW-1300
  Code Cleanup
  Bug
  ChangeLog
  TW-1301
  Bug TW-1302
  Diagnostics
  Bug TW-1254
  Documentation
  Bug TW-1295
  ...
Merging in latest from upstream (TM/task:refs/heads/2.4.0)

* commit '75f938463e588b9cc3b603446d2670ef3ee44e36':
  TW-285
Rename method to match the current testing API
Refactor testing framework to allow using callTask* methods inside @classmethods
Refactor some tests to avoid redoing setUp/tearDown once per test
Merge pull request #2 in TM/task from ~UNODE/task:2.4.0 to 2.4.0

* commit '13d79618136a3aa1c5e97c19af2d20100a31415e':
  Refactor some tests to avoid redoing setUp/tearDown once per test
  Refactor testing framework to allow using callTask* methods inside @classmethods
  Rename method to match the current testing API
  Tests - Include task stdout/err if exit code != 0