Merge remote-tracking branch 'origin/master'

bin/compile

@@ -180,7 +180,7 @@ sub-env $BIN_DIR/steps/collectstatic
 set-env PATH '$HOME/.heroku/python/bin:$PATH'
 set-env PYTHONUNBUFFERED true
 set-env PYTHONHOME /app/.heroku/python
-set-env LIBRARY_PATH /app/.heroku/vendor/lib:/app/.heroku/python/lib
+set-env LIBRARY_PATH '/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LIBRARY_PATH'
 set-env LD_LIBRARY_PATH '/app/.heroku/vendor/lib:/app/.heroku/python/lib:$LD_LIBRARY_PATH'
 set-default-env LANG en_US.UTF-8
 set-default-env PYTHONHASHSEED random