Espree vulnerability issues

[hugoluchessi]

protobuf.js version: 6.8.6

According to https://www.npmjs.com/advisories/1488, this version of acorn, which is a dependency for Espree, has a vulnerability on versions prior to 5.7.4, 6.4.1, 7.1.1.

Espree has just release version 6.2.1 which fixes this issue.

Outcome:
npm audit outputs an error message regarding moderate issues.

[bcoe]

👋 @hugoluchessi could you try running @protobufjs@6.8.9, I believe it should have this patched already.