Updated CHANGES.md in prep for 0.15.0 release
Updated CHANGES.md in prep for 0.15.0 release

allenday/adam,allenday/adam,kcompher/adam,erictu/adam,FusionWorks/adam,laserson/adam,heuermh/adam,massie/adam,massie/adam,heuermh/adam,bigdatagenomics/adam,VinACE/adam,gazimahmud/adam,massie/adam,gazimahmud/adam,SwathiMystery/adam,gazimahmud/adam,VinACE/adam,rnpandya/adam,massie/adam,laserson/adam,erictu/adam,rnpandya/adam,heuermh/adam,kcompher/adam,tdanford/adam,SwathiMystery/adam,bigdatagenomics/adam,tdanford/adam,SwathiMystery/adam,kcompher/adam,laserson/adam,tomwhite/adam,laserson/adam,erictu/adam,allenday/adam,FusionWorks/adam,FusionWorks/adam,gazimahmud/adam,bigdatagenomics/adam,erictu/adam,VinACE/adam,tomwhite/adam,FusionWorks/adam,tomwhite/adam,tdanford/adam,allenday/adam,kcompher/adam,tdanford/adam,bigdatagenomics/adam,SwathiMystery/adam,rnpandya/adam,tomwhite/adam,rnpandya/adam,VinACE/adam,heuermh/adam