polyfill.io User Agent normaliser

This is the VCL & JS implementation of the User-Agent normalisation used within the polyfill-service and the polyfill-library.

Usage

For a request which was the user-agent Chrome 71.1:

Example in VCL

``vcl
import "normalise-user-agent.vcl";

sub vcl_recv {
call normalise_user_agent_1_0_6;

req.http.normalized_user_agent_family = "chrome";

req.http.normalized_user_agent_major_version = "71";

req.http.normalized_user_agent_minor_version = "1";

req.http.normalized_user_agent_patch_version = "0";

req.http.Normalized-User-Agent = "chrome/71.1.0";

}
`

Example in JS

`js
const UA = require('@lincy/polyfill-useragent-normaliser');

const useragent = new UA(request.headers['user-agent']);
console.log(useragent.isUnknown()); // false
console.log(useragent.satisfies("<50")); // false
console.log(useragent.satisfies(">50")); // true
``