Simplify module load

[soichih]

This if statement > https://github.com/brain-life/app-FSLBET/blob/198cdd673c7aa8675d4ea4023fa01c61c18f64c9/main#L6

Can be simplified to following..

which module && module load fsl

which will return true if module command exists, if it does, it just loads it. I think we should avoid checking for $ENV which might not be set properly on some environment.

[kitchell]

Ok. checking for ENV was the standard as far as I know, are we keeping track of these changes anywhere?

[soichih]

I haven't changed the way ENVs are set, but I think we should shoot for deprecating them eventually. I think we should make apps to discover its own environment as much as possible. This app can easily be docker-ized (just apt install fsl with neurodebian base) and when we do, we don't need to rely on any external dependencies.