use .eslintrc.json/.cjs rather than .eslintrc.js

[warner]

To support #527, we need to make sure all our .js files are ES6-module format (with import and export), rather than CommonJS format (with require and exports.foo= and module.exports=). This includes the config files we use for ESLint, which so far have been CommonJS format.

The task is to rewrite them into JSON, and rename them to .json instead of .js. I'm pretty sure this includes our new .eslintrc-jessie.js files, but I'm not entirely sure how those get composed or loaded.

• acorn-eventual-send
• agoric-cli
• assert
• autoswap-frontend
• bundle-source
• captp
• cosmic-swingset
• default-evaluate-options
• deployment
• ERTP
• evaluate
• eventual-send
• import-manager
• make-promise
• marshal
• pixel-demo
• registrar
• same-structure
• sharing-service
• sparse-ints
• spawner
• store
• SwingSet
• swingset-runner
• tame-metering
• transform-eventual-send
• transform-metering
• wallet-frontend
• weak-store
• zoe

[warner]

@michaelfig pointed out that we can just rename the files to .eslintrc.cjs instead, and keep using the CommonJS syntax. Also that our Jessie linting will require more than the JSON-based configuration.

[katelynsills]

Can we close this? I couldn't find any eslintrc.js files