Update Heroku.md
Update Heroku.md

> WARNING: `heroku addons:add` has been deprecated. Please use `heroku addons:create` instead.
Koronen/stringer,dperson/stringer,jeroenj/stringer,swanson/stringer,jqr/stringer,jeroenj/stringer,swanson/stringer,dperson/stringer,Koronen/stringer,dperson/stringer,swanson/stringer,run-project/stringer,nobuti/stringer,nibble/stringer,swanson/stringer,nibble/stringer,jqr/stringer,run-project/stringer,geemus/stringer,jeroenj/stringer,jqr/stringer,Koronen/stringer,nibble/stringer,jeroenj/stringer,Koronen/stringer,jqr/stringer,nobuti/stringer,nibble/stringer,geemus/stringer,geemus/stringer,run-project/stringer,dperson/stringer,geemus/stringer,nobuti/stringer