add env var blacklist
add env var blacklist

bskyb-commerce/ruby-buildpack,cloudfoundry/ruby-buildpack,zunda/heroku-buildpack-ruby,orlando/heroku-buildpack-ruby,DyegoCosta/heroku-buildpack-ruby,codykrieger/heroku-buildpack-jekyll,Altoros/ruby-buildpack,HYPERHYPER/heroku-buildpack-ruby,dtao/teeny-buildpack,dtao/deft-buildpack-ruby,schu/heroku-buildpack-ruby,bwaite-jaroop/heroku-buildpack-ruby,recursecenter/heroku-buildpack-ruby,lyoshenka/heroku-buildpack-ruby-jekyll,jumptvs/BP_Ruby,crdschurch/heroku-buildpack-ruby,zoomer/heroku-buildpack-ruby-bower,dieze/heroku-buildpack-ruby-hooks,bellycard/heroku-buildpack-ruby,cloudn/buildpack-ruby,Git-Host/prelang-buildpack,Genius/heroku-buildpack-ruby,Genius/heroku-buildpack-ruby,fgbreel/heroku-buildpack-ruby,mrhenry/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack,shuber/heroku-buildpack-ruby,hixi/heroku-buildpack-ruby,ekaranto/rails4-bluemix-buildpack,orlando/heroku-buildpack-ruby,trumaker/heroku-buildpack-turbo-sprockets,jumptvs/BP_Ruby,hatofmonkeys/ruby-testing-buildpack,bskyb-commerce/help-heroku-buildpack,iamjarvo/ruby-buildpack,awebneck/heroku-buildpack-canvas,recursecenter/heroku-buildpack-ruby,cloudn/buildpack-ruby,ablease/custom-buildpack,cordata/heroku-buildpack-ruby,bskyb-commerce/help-heroku-buildpack,mintybit/heroku-buildpack-ruby,barakav/heroku-buildpack-ruby,cmaggard/heroku-buildpack-turbo-sprockets,jasonlevens/heroku-buildpack-ruby,moneyadviceservice/heroku-buildpack-ruby-bowndler,ibmdb/db2rubybuildpack,gbenedict/heroku-buildpack-ruby,DouglasAllen/heroku-buildpack-ruby,righi/instacart-heroku-buildpack,michaelphines/alexa-nest,anay/buildpack-ruby-with-oracle-jdk,guidance-guarantee-programme/heroku-buildpack-princexml-old,takii/db2rubybuildpack,DigitalInnovation/heroku-buildpack-mslabs,bellycard/heroku-buildpack-ruby,jonseaberg/heroku-buildpack-turbo-sprockets,hpcloud/ruby-buildpack,hixi/heroku-buildpack-ruby,KoanHealth/heroku-buildpack-marvin-setup,cloudfoundry/ruby-buildpack,derrek/heroku-buildpack-ruby,markaschneider/heroku-buildpack-ruby-ffmpeg-sox,orenyk/heroku-buildpack-ruby,allomov/fat-free-heroku-buildpack-ruby,Altoros/ruby-buildpack,icelab/heroku-buildpack-ruby,ndbroadbent/heroku-buildpack-turbo-sprockets,ablease/custom-buildpack,qnyp/heroku-buildpack-ruby-bower,mattwalters/heroku-buildpack-ruby,cloudControl/buildpack-ruby,sky-uk/ruby-buildpack,0x00evil/heroku-buildpack-ruby,ekaranto/rails4-bluemix-buildpack,iamjarvo/ruby-buildpack,hpcloud/ruby-buildpack,daltonrenaldo/heroku-buildpack-ruby,zidekmat/buildpack-ruby,sky-uk/ruby-buildpack,dleavitt/heroku-buildpack-ruby,dtao/teeny-buildpack,mperejda/heroku-buildpack-ruby,ibmdb/db2rubybuildpack,HYPERHYPER/heroku-buildpack-ruby,CPPWind/ruby-buildpack,heroku/heroku-buildpack-ruby,vhx/heroku-buildpack,d-reinhold/cf-buildpack-ruby,dlorson/gentle-buildpack,mattmanning/heroku-buildpack-ruby-jekyll,hatofmonkeys/ruby-testing-buildpack,Jonty/ruby-buildpack,pilotcreative/heroku-buildpack-ruby,scottatron/moc-buildpack,ilpoldo/heroku-buildpack-ruby,Jonty/ruby-buildpack,musicglue/heroku-buildpack-ruby,zunda/heroku-buildpack-ruby,mattmanning/heroku-buildpack-ruby-jekyll,dieze/heroku-buildpack-ruby-hooks,blueapron/heroku-buildpack-ruby,ericboehs/heroku-buildpack-ruby,ericboehs/heroku-buildpack-ruby,beydogan/ruby-buildpack,wakermahmud/heroku-buildpack-jekyll,cloudn/buildpack-ruby,jayshreeanand/heroku-buildpack-ruby,andycroll/heroku-buildpack-jekyll,Jonty/ruby-buildpack,leonardykris/mos-ruby-buildpack,mattwalters/heroku-buildpack-ruby,hpcloud/ruby-buildpack,sky-uk/help-heroku-buildpack,ilpoldo/heroku-buildpack-ruby,instacart/heroku-buildpack-ruby,jonseaberg/heroku-buildpack-turbo-sprockets,mrhenry/heroku-buildpack-ruby,KoanHealth/heroku-buildpack-marvin-setup,stolt45/heroku-buildpack-ruby-with-sqlite3,DigitalInnovation/heroku-buildpack-mslabs,redhotvengeance/heroku-buildpack-deep-thought,Dim25/heroku-buildpack-ruby-GSL,0x00evil/heroku-buildpack-ruby,ltrademark/heroku-buildpack-ruby,takii/heroku-buildpack-ruby,Jonty/ruby-buildpack,engineyard/heroku-buildpack-ruby,Scalingo/ruby-buildpack,hellojustin/heroku-buildpack-custom-ruby,brightbytes/heroku-buildpack-ruby-without-assets-precompile,trumaker/heroku-buildpack-turbo-sprockets,ruby/heroku-buildpack-www-ruby-lang,markaschneider/heroku-buildpack-ruby-ffmpeg-sox,daltonrenaldo/heroku-buildpack-ruby,tdenovan/heroku-buildpack-ruby,teodor-pripoae/heroku-buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk,pkgr/heroku-buildpack-ruby,dleavitt/heroku-buildpack-ruby,Micka33/heroku-buildpack-ruby-liblua,bskyb-commerce/ruby-buildpack,DouglasAllen/heroku-buildpack-ruby,moneyadviceservice/heroku-buildpack-ruby-bowndler,Nedomas/heroku-buildpack-ruby-minus-node-with-node-paths,bskyb-commerce/ruby-buildpack,pietrop/heroku-buildpack-ruby,CPPWind/ruby-buildpack,amaltson/heroku-buildpack-ruby,catalyzeio/buildpack-ruby,erintherad/heroku-buildpack-ruby,scottatron/moc-buildpack,dlorson/gentle-buildpack,makifund/heroku-buildpack-ruby,fcruxen/ruby-buildpack,codykrieger/heroku-buildpack-jekyll,ndbroadbent/heroku-buildpack-turbo-sprockets,electricobjects/heroku-buildpack-ruby,mperejda/heroku-buildpack-ruby,gls1/heroku-buildpack-ruby-pdftk-new,stolt45/heroku-buildpack-ruby-with-sqlite3,cloudControl/buildpack-ruby,amaltson/heroku-buildpack-ruby,cloudn/buildpack-ruby,diasks2/heroku-buildpack-mecab,redhotvengeance/heroku-buildpack-deep-thought,heroku/heroku-buildpack-ruby,lyoshenka/heroku-buildpack-ruby-jekyll,wakermahmud/heroku-buildpack-jekyll,ibmdb/db2rubybuildpack,sstelfox/buildpack-ruby,instacart/heroku-buildpack-ruby,catalyzeio/buildpack-ruby,sky-uk/ruby-buildpack,cordata/heroku-buildpack-ruby,beydogan/ruby-buildpack,ablease/custom-buildpack,qstream/heroku-buildpack-ruby,swipesense/heroku-buildpack-ruby,schu/heroku-buildpack-ruby,michaelphines/alexa-nest,gls1/heroku-buildpack-ruby-pdftk-new,bwaite-jaroop/heroku-buildpack-ruby,pilotcreative/heroku-buildpack-ruby,qstream/heroku-buildpack-ruby,schu/buildpack-testing,Altoros/ruby-buildpack,ablease/custom-buildpack,reesio/heroku-buildpack-ruby,allomov/fat-free-heroku-buildpack-ruby,brightbytes/heroku-buildpack-ruby-without-assets-precompile,barakav/heroku-buildpack-ruby,tdenovan/heroku-buildpack-ruby,aarongray/heroku-buildpack-ruby,mintybit/heroku-buildpack-ruby,jumptvs/BP_Ruby,CPPWind/ruby-buildpack,fcruxen/ruby-buildpack,tenjikinc/heroku-buildpack-ruby,electricobjects/heroku-buildpack-ruby,pietrop/heroku-buildpack-ruby,awebneck/heroku-buildpack-canvas,tenjikinc/heroku-buildpack-ruby,bskyb-commerce/ruby-buildpack,diasks2/heroku-buildpack-mecab,Nedomas/heroku-buildpack-ruby-minus-node-with-node-paths,crdschurch/heroku-buildpack-ruby,dtao/deft-buildpack-ruby,ChefSteps/heroku-buildpack-ruby,stefansundin/heroku-buildpack-ruby,simonnordberg/heroku-buildpack-ruby,jasonlevens/heroku-buildpack-ruby,makifund/heroku-buildpack-ruby,takii/db2rubybuildpack,zidekmat/buildpack-ruby,ericroberts/heroku-buildpack-ruby,shuber/heroku-buildpack-ruby,packetmonkey/heroku-buildpack-ruby,rowanoulton/heroku-buildpack-ruby,hpcloud/ruby-buildpack,qnyp/heroku-buildpack-ruby-bower,hellojustin/heroku-buildpack-custom-ruby,gls1/heroku-buildpack-ruby-pdftk,derrek/heroku-buildpack-ruby,ericroberts/heroku-buildpack-ruby,zoomer/heroku-buildpack-ruby-bower,donnykurnia/heroku-buildpack-ruby,jgable/buildpack-ruby-rack-setup-tasks,stefansundin/heroku-buildpack-ruby,jayshreeanand/heroku-buildpack-ruby,takii/heroku-buildpack-ruby,sky-uk/help-heroku-buildpack,iamjarvo/ruby-buildpack,blueapron/heroku-buildpack-ruby,teodor-pripoae/heroku-buildpack-ruby,ltrademark/heroku-buildpack-ruby,d-reinhold/cf-buildpack-ruby,space150/heroku-buildpack-ruby,icelab/heroku-buildpack-ruby,fgbreel/heroku-buildpack-ruby,ChefSteps/heroku-buildpack-ruby,orenyk/heroku-buildpack-ruby,rowanoulton/heroku-buildpack-ruby,Dim25/heroku-buildpack-ruby-GSL,gbenedict/heroku-buildpack-ruby,righi/instacart-heroku-buildpack,engineyard/heroku-buildpack-ruby,pkgr/heroku-buildpack-ruby,Micka33/heroku-buildpack-ruby-liblua,schu/buildpack-testing,fcruxen/ruby-buildpack,samfrench/heroku-buildpack-ruby,guidance-guarantee-programme/heroku-buildpack-princexml-old,andycroll/heroku-buildpack-jekyll,ekaranto/rails4-bluemix-buildpack,jumptvs/BP_Ruby,cmaggard/heroku-buildpack-turbo-sprockets,jgable/buildpack-ruby-rack-setup-tasks,simonnordberg/heroku-buildpack-ruby,takii/db2rubybuildpack,aarongray/heroku-buildpack-ruby,CPPWind/ruby-buildpack,Scalingo/ruby-buildpack,iamjarvo/ruby-buildpack,space150/heroku-buildpack-ruby,d-reinhold/cf-buildpack-ruby,hatofmonkeys/ruby-testing-buildpack,takii/db2rubybuildpack,DyegoCosta/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack,ekaranto/rails4-bluemix-buildpack,leonardykris/mos-ruby-buildpack,tpope/heroku-buildpack-ruby-tpope,Git-Host/prelang-buildpack,samfrench/heroku-buildpack-ruby,musicglue/heroku-buildpack-ruby,fcruxen/ruby-buildpack,jonasoberschweiber/heroku-buildpack-ruby,sstelfox/buildpack-ruby,donnykurnia/heroku-buildpack-ruby,reesio/heroku-buildpack-ruby,vhx/heroku-buildpack,jonasoberschweiber/heroku-buildpack-ruby,anay/buildpack-ruby-with-oracle-jdk,sky-uk/ruby-buildpack,tpope/heroku-buildpack-ruby-tpope,swipesense/heroku-buildpack-ruby,Altoros/ruby-buildpack,erintherad/heroku-buildpack-ruby,packetmonkey/heroku-buildpack-ruby,cloudfoundry/ruby-buildpack