support for proxy config

16:23 $ npm-check

autosuggest-highlight      ⛔️  NPM ERR!  Registry error getaddrinfo ENOTFOUND registry.npmjs.org registry.npmjs.org:443
...

both env http_proxy, https_proxy (lower and uppercasE) and npm proxy and https_proxy are setup.

I guess this is because of @sindresorhus 's package-json - see https://github.com/sindresorhus/package-json/blob/master/index.js#L13

[robmcguinness]

Also behind a proxy and use npm-check frequently. My temporary workaround is to manually edit npm-check/node_modules/package-json/index.js:

var caw = require('caw');
return got(pkgUrl, {
  json: true,
  headers: headers,
  agent: caw()
})

[thtliife]

Thanks @robmcguinness for the fix with caw. I have forked the original package-json, and made the changes you suggested in the fork. Anyone requiring an easier fix, see the “Usage” section in the readme