Channel order transpose, for image embedder. Updated unit test. (#87)

rl_coach/tests/architectures/mxnet_components/embedders/test_image_embedder.py

@@ -15,7 +15,8 @@ def test_image_embedder():
     params = InputEmbedderParameters(scheme=EmbedderScheme.Medium)
     emb = ImageEmbedder(params=params)
     emb.initialize()
-    input_data = mx.nd.random.uniform(low=0, high=1, shape=(10, 3, 244, 244))
+    # input is NHWC, and not MXNet default NCHW
+    input_data = mx.nd.random.uniform(low=0, high=1, shape=(10, 244, 244, 3))
     output = emb(input_data)
     assert len(output.shape) == 2  # since last block was flatten
     assert output.shape[0] == 10  # since batch_size is 10