Required peer dependencies are not installed

[josebolos]

After upgrading shunter from @springernature/eslint-config@0.1.0 to @springernature/eslint-config@1.0.0, running npm install returns the following:

npm WARN @springernature/eslint-config@1.0.0 requires a peer of eslint-plugin-jest@^21.13.0 but none is installed. You must install peer dependencies yourself.

Relevant bits of the .eslintrc file:

"extends": [
    "@springernature/eslint-config",
    "@springernature/eslint-config/node"
],

I didn't add eslint-plugin-jest to shunter's devDependencies as I didn't realise it's necessary.

We need to:

• assess the potential impact of having / not having that peer dependency included, and
• change the docs to clarify if the dependency is needed in any case, and why.