Fix build script

[AquiGorka]

yarn build produces this output:

Failed to compile.
Failed to minify the code from this file:
        ./node_modules/cids/src/index.js:23
Read more here: http://bit.ly/2tRViJ9
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.

References:

• Webpack bundle failing at CID: Unexpected token: name (CID) multiformats/js-cid#38
• Revisit targeting ES6+ facebook/create-react-app#2108
• Checking for WebSockets constructor name fails under uglification libp2p/js-libp2p#65

Our yarn build script is broken until we figure this one out.

[chadoh]

I'm feeling incapable when trying to get good info on where exactly this error happens and how to fix it. I have made basically no progress on this bug today. 😞