ACER algorithm (#184)

* initial ACER commit

* Code cleanup + several fixes

* Q-retrace bug fix + small clean-ups

* added documentation for acer

* ACER benchmarks

* update benchmarks table

* Add nightly running of golden and trace tests. (#202)

Resolves #200

* comment out nightly trace tests until values reset.

* remove redundant observe ignore (#168)

* ensure nightly test env containers exist. (#205)

Also bump integration test timeout

* wxPython removal (#207)

Replacing wxPython with Python's Tkinter.
Also removing the option to choose multiple files as it is unused and causes errors, and fixing the load file/directory spinner.

* Create CONTRIBUTING.md (#210)

* Create CONTRIBUTING.md.  Resolves #188

* run nightly golden tests sequentially. (#217)

Should reduce resource requirements and potential CPU contention but increases
overall execution time.

* tests: added new setup configuration + test args (#211)

- added utils for future tests and conftest
- added test args

* new docs build

* golden test update

rl_coach/architectures/tensorflow_components/architecture.py

@@ -350,7 +350,7 @@ class TensorFlowArchitecture(Architecture):
                 importance_weight = np.ones(target_ph.shape[0])
             else:
                 importance_weight = importance_weights[placeholder_idx]
-            importance_weight = np.reshape(importance_weight, (-1,) + (1,)*(len(target_ph.shape)-1))
+            importance_weight = np.reshape(importance_weight, (-1,) + (1,) * (len(target_ph.shape) - 1))
 
             feed_dict[self.importance_weights[placeholder_idx]] = importance_weight