Fix an issue where default requirements.txt wasn't being set
Fix an issue where default requirements.txt wasn't being set

thedotpost/heroku-buildpack-pelican,Girbons/buildpack-mkdocs,getpelican/heroku-buildpack-pelican,getpelican/heroku-buildpack-pelican,ckcollab/heroku-buildpack-pelican,wics-uw/heroku-buildpack-pelican,ckcollab/heroku-buildpack-pelican,pyladies-brazil/heroku-buildpack-pelican,ronert/heroku-buildpack-pelican,ipartola/heroku-buildpack-pelican,thedotpost/heroku-buildpack-pelican,wics-uw/heroku-buildpack-pelican,tpmanley/heroku-buildpack-pelican,Girbons/buildpack-mkdocs,pyladies-brazil/heroku-buildpack-pelican,tpmanley/heroku-buildpack-pelican,ipartola/heroku-buildpack-pelican,ronert/heroku-buildpack-pelican