fix!: replace process.cwd() with "/"

[waynevanson]

THIS IS A BREAKING CHANGE

process is not a global in the browser and seems like a left over implementation detail when transferred from NodeJS.

There are two options to choose from as solutions:

1. Throw an error instead of calling process.cwd().
2. Replace process.cwd() with the root directory "/".

I've chosen the latter because it's the first thing that came to mind, but will happily do the first if that's desired.

• Closes Error in browser: process is not defined #29
• Closes TypeError: process.cwd is not a function #32