Kill Goerli

[adamgall]

Closes #79

• Remove all references to Goerli (except deployment artifacts... but we probably don't need these any longer)
• Update test suite so that it doesn't have a dependency on Goerli. In fact, it no longer has a dependency on any public network.

To test:

rm -rf node_modules 
nvm use
npm install
npm run clean
npm run compile
npm run test