CustomClassifier doesn't handle channel-free models

[AlliedToasters]

An issue was brought to my attention that appears to be related to custom classifier models that do not expect color channels in input images. A test case has been added in the branch custom_classifier that reproduces this issue with the following traceback:

E

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ERROR: test_custom_classifier (__main__.TestImageFlow)
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Traceback (most recent call last):
  File "/Users/mklear/PyCDA/test.py", line 125, in test_custom_classifier
    cls = CustomClassifier('./pycda/models/no_channels_model.h5', crater_pixels=6)
  File "/Users/mklear/PyCDA/pycda/classifiers.py", line 66, in __init__
    self.input_channels = input_layer.input_shape[3]
IndexError: tuple index out of range

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Ran 11 tests in 3.570s

FAILED (errors=1)

I am currently working to solve this issue.