put info regarding submodules, and remove older version of pysam dependency.
put info regarding submodules, and remove older version of pysam dependency.

jreveillaud/meren.github.io,jreveillaud/meren.github.io,merenlab/web,merenlab/web,jreveillaud/meren.github.io,merenlab/web,jreveillaud/meren.github.io,merenlab/web,merenlab/web,jreveillaud/meren.github.io,merenlab/web