Fixed example OPF command on README.md; referenced unset environment variable $NUPIC_HOME
Fixed example OPF command on README.md; referenced unset environment variable $NUPIC_HOME

cngo-github/nupic,marionleborgne/nupic,virneo/nupic,passiweinberger/nupic,lscheinkman/nupic,go-bears/nupic,eranchetz/nupic,wanghaven/nupic,elkingtonmcb/nupic,jcasner/nupic,cngo-github/nupic,EricSB/nupic,markneville/nupic,darshanthaker/nupic,runt18/nupic,ywcui1990/nupic,alfonsokim/nupic,fergalbyrne/nupic,vamsirajendra/nupic,chen0031/nupic,lscheinkman/nupic,GeraldLoeffler/nupic,badlogicmanpreet/nupic,numenta/nupic,SaganBolliger/nupic,neuroidss/nupic,rayNymous/nupic,metaml/nupic,darshanthaker/nupic,pulinagrawal/nupic,BeiLuoShiMen/nupic,glorizen/nupic,akhilaananthram/nupic,ben-hopps/nupic,jcasner/nupic,akhilaananthram/nupic,cngo-github/nupic,chanceraine/nupic,marionleborgne/nupic,mcanthony/nupic,glorizen/nupic,EricSB/nupic,markneville/nupic,brev/nupic,lscheinkman/nupic,rayNymous/nupic,rhyolight/nupic,brev/nupic,numenta-ci/nupic,jcasner/nupic,pap/nupic,numenta/nupic,mcanthony/nupic,sambitgaan/nupic,alfonsokim/nupic,go-bears/nupic,elkingtonmcb/nupic,sambitgaan/nupic,arhik/nupic,breznak/nupic,cogmission/nupic,numenta-ci/nupic,chen0031/nupic,subutai/nupic,blueburningcoder/nupic,breznak/nupic,pulinagrawal/nupic,brev/nupic,numenta/nupic,sambitgaan/nupic,vitaly-krugl/nupic,akhilaananthram/nupic,chanceraine/nupic,SaganBolliger/nupic,marionleborgne/nupic,rayNymous/nupic,wanghaven/nupic,BoltzmannBrain/nupic,allanino/nupic,ywcui1990/nupic,rhyolight/nupic,numenta-ci/nupic,subutai/nupic,BoltzmannBrain/nupic,ben-hopps/nupic,vitaly-krugl/nupic,loretoparisi/nupic,allanino/nupic,runt18/nupic,SaganBolliger/nupic,BeiLuoShiMen/nupic,wanghaven/nupic,pap/nupic,BoltzmannBrain/nupic,fergalbyrne/nupic,blueburningcoder/nupic,loretoparisi/nupic,virneo/nupic,scottpurdy/nupic,runt18/nupic,alfonsokim/nupic,breznak/nupic,vitaly-krugl/nupic,metaml/nupic,arhik/nupic,cogmission/nupic,eranchetz/nupic,darshanthaker/nupic,glorizen/nupic,vamsirajendra/nupic,badlogicmanpreet/nupic,ywcui1990/nupic,neuroidss/nupic,rcrowder/nupic,passiweinberger/nupic,pap/nupic,rcrowder/nupic,fergalbyrne/nupic,chanceraine/nupic,ben-hopps/nupic,neuroidss/nupic,markneville/nupic,blueburningcoder/nupic,BeiLuoShiMen/nupic,rcrowder/nupic,loretoparisi/nupic,subutai/nupic,scottpurdy/nupic,passiweinberger/nupic,cogmission/nupic,vamsirajendra/nupic,mcanthony/nupic,rhyolight/nupic,metaml/nupic,EricSB/nupic,GeraldLoeffler/nupic,pulinagrawal/nupic,elkingtonmcb/nupic,badlogicmanpreet/nupic,scottpurdy/nupic,allanino/nupic,virneo/nupic,GeraldLoeffler/nupic,eranchetz/nupic,arhik/nupic,chen0031/nupic,go-bears/nupic