Option to change bedgraphToBigwig path

[agalitsyna]

I usually run notebooks with bioframe in other environments from running notebooks, and there is no simple way to change the path to some binaries run as subprocessed in bioframe, e.g. here:

bioframe/bioframe/io/fileops.py

Lines 540 to 544 in cad9942

	p = subprocess.run(
	["bedGraphToBigWig", f.name, cs.name, outpath],
	stdout=subprocess.PIPE,
	stderr=subprocess.PIPE,
	)

Having an option to pass the path will be great.