Typo in readme.md

[codemaker4]

Hi Ryan,

I watched your talk at Fosdem, it was awesome!

I saw this in your readme.md:

Customizable: Go pot can be customized to respond with different different response times.

"Different" is written twice, it should only be there once.

Have a nice day!

[ryanolee]

Thanks for taking an interest!
Will roll this up into the documentation changes made in #29 for simplicity's sake!