Update babel and eslint config

[kimanijacky]

Update the following packages:

• babel-preset-metalab
• eslint-config-metalab
• eslint
• eslint-plugin-babel
• eslint-plugin-filenames
• eslint-plugin-import
• eslint-plugin-lodash-fp
• eslint-plugin-react

[10xjs]

@andela-jkimani babel-preset-metalab 6 is a breaking change over 5. We need to update the .babelrc file with targets to ensure compatibility (babel-preset-metalab uses babel-preset-env internally) . See https://github.com/babel/babel-preset-env#targets.

[10xjs]

@izaakschroeder What do you think is a sane browser target? "last 3 versions"? "last 4 versions"? ...

I assume we want to capture IE 8 and Safari 7 and whatever else.

Ideally this would be the same as what this lib currently supports, whatever that is exactly 😬 .

[izaakschroeder]

Having ["> 1%"] seems reasonable to me for now. What do you figure?

[10xjs]

It would be nice if there was a browserslist.lock since the result of ["> 1%"] is a product of when it is calculated.

[kimanijacky]

@izaakschroeder So we're not targeting specific browsers? Got it!