102 patternmarkers all returning empty lists

[dimalvovs]

• add a test that fails on empty patterMarkers
• make it pass by rewriting the method for threshold='all'

[dimalvovs]

@kwoyshner can you review please?

[kwoyshner]

I tried reinstalling from this branch and was able to get patternMarkers with 'all' now, thank you!

[dimalvovs]

@kwoyshner do you want to have a look at threshold = 'cut'? I've updated it too. This part of code is poorly documented so I was not sure what that mode should do but there was a dimension mismatch. simplicityGENES function needs to be inspected for functionality.