feat: Relax react rules
feat: Relax react rules

- class-methods-use-this to warn and with react exceptions (https://github.com/peerigon/eslint-config-peerigon/issues/12)
- prefer-stateless-function to warn because it should be a hint
- react-in-jsx-scope to off because the React variable can be injected with webpack

peerigon/eslint-config-peerigon,peerigon/eslint-config-peerigon,peerigon/eslint-config-peerigon