Add Procfile
Add Aptfile and add heroku-buildpack-apt to .buildpacks
Add libdbus-glib-1-2 to Aptfile
Add vendorbinaries buildpack
Add xvfb vendor binary url to .vendor_urls
Specify listen port by PORT environment variable
Return image asynchronized
Add xvfb-run
Add slimerjs download url to .vendor_urls
Fix Procfile for web
Loggin server port
Pass port by argument
Better logging
output debug message
logging env
Add slimerweb sh to run xvfb and slimerjs