Change Heroku instructions in wzrd.in to refer to production instead of master

[mpj]

Master is broken and cannot be deployed on Heroku and it took me a little while figure that out. Better include in the instructions that the production branch should be used, not master.

[jfhbrook]

master cannot be installed on heroku, and that is intentional.

[jfhbrook]

It occurs to me that the front page of wzrd.in has the old README in it. Opening this in the chance that someone feels like fixing this.