remove assertion that waveforms must have 8 digital outputs

[swharden]

Dan Orlin sent-in a report that pyABF throws an exception when loading 2015_09_10_0001.abf

File "pyabf/waveform.py", line 142, in addEpoch
    assert len(digitalState) == _DIGITAL_OUTPUT_COUT
AssertionError

That line is here:

pyABF/src/pyabf/waveform.py

Line 142 in dc45763

assert len(digitalState) == _DIGITAL_OUTPUT_COUT

Embarrassingly there is a variable name in the typo, as "cout" should be "count".

Interestingly, that abf/line doesn't throw an exception in Pyhthon 3.6, 3.7, or 3.6 on Linux, MacOS, or Windows in the automated build system 🤔

I'm thinking that this may be a numpy-version-specific error. Dan is using pyabf 2.2.4 on a 1.5 year old version of Anaconda (Python: 3.6.8, Dec 29 2018).

Solution

Dan said that commenting-out this assertion fixed the problem, so let's replace this assertion with a non-crashing warning.