[ADAM-1398] Delete adam-scripts/R.
[ADAM-1398] Delete adam-scripts/R.

Resolves #1398.

massie/adam,heuermh/adam,laserson/adam,laserson/adam,bigdatagenomics/adam,laserson/adam,heuermh/adam,massie/adam,heuermh/adam,laserson/adam,bigdatagenomics/adam,massie/adam,heuermh/adam,massie/adam,bigdatagenomics/adam,bigdatagenomics/adam