Support for SARIF format

[Barroqueiro]

Hi! When running the following command

docker run -it --rm -v $(pwd):/data cytopia/eslint -f sarif .

This error message appears:

There was a problem loading formatter: /usr/local/lib/node_modules/eslint/lib/cli-engine/formatters/sarif
Error: Cannot find module '/usr/local/lib/node_modules/eslint/lib/cli-engine/formatters/sarif'
Require stack:
- /usr/local/lib/node_modules/eslint/lib/cli-engine/cli-engine.js
- /usr/local/lib/node_modules/eslint/lib/eslint/eslint.js
- /usr/local/lib/node_modules/eslint/lib/eslint/index.js
- /usr/local/lib/node_modules/eslint/lib/cli.js
- /usr/local/lib/node_modules/eslint/bin/eslint.js