Adding citation information to README.
Adding citation information to README.

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