title: Unable to npm install Angular-cli after proxy configuration
body: <p>I am trying to download Angular in Windows 10 using npm install. As I am on corporate proxy, I configured the proxy to username:password@server:port</p>
  
  <p>However, I am facing this issue when running</p>
  
  <p><code>npm ERR! code E407
  npm ERR! 407 Proxy Authorization Required: @angular/cli@latest</code></p>
  
  <p>The debug log as followed:</p>
  
  <pre><code>0 info it worked if it ends with ok
  1 verbose cli [ 'C:\\Program Files\\nodejs\\node.exe',
  1 verbose cli   'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',
  1 verbose cli   '--proxy',
  1 verbose cli   'http://XXXXX',     //Removed my proxy details
  1 verbose cli   '--without-ssl',
  1 verbose cli   '--insecure',
  1 verbose cli   '-g',
  1 verbose cli   'install',
  1 verbose cli   '@angular/cli' ]
  2 info using npm@5.4.2
  3 info using node@v8.8.1
  4 verbose npm-session 40ab1dc3dabb6029
  5 silly install loadCurrentTree
  6 silly install readGlobalPackageData
  7 http fetch GET 407 http://registry.npmjs.org/@angular%2fcli 109ms
  8 silly fetchPackageMetaData error for @angular/cli@latest 407 Proxy Authorization Required: @angular/cli@latest
  9 verbose stack Error: 407 Proxy Authorization Required: @angular/cli@latest
  9 verbose stack     at fetch.then.res (C:\Program Files\nodejs\node_modules\npm\node_modules\pacote\lib\fetchers\registry\fetch.js:42:19)
  9 verbose stack     at tryCatcher (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\util.js:16:23)
  9 verbose stack     at Promise._settlePromiseFromHandler (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:512:31)
  9 verbose stack     at Promise._settlePromise (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:569:18)
  9 verbose stack     at Promise._settlePromise0 (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:614:10)
  9 verbose stack     at Promise._settlePromises (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\promise.js:693:18)
  9 verbose stack     at Async._drainQueue (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\async.js:133:16)
  9 verbose stack     at Async._drainQueues (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\async.js:143:10)
  9 verbose stack     at Immediate.Async.drainQueues (C:\Program Files\nodejs\node_modules\npm\node_modules\bluebird\js\release\async.js:17:14)
  9 verbose stack     at runCallback (timers.js:785:20)
  9 verbose stack     at tryOnImmediate (timers.js:747:5)
  9 verbose stack     at processImmediate [as _immediateCallback] (timers.js:718:5)
  10 verbose cwd C:\Users\XXXXX
  11 verbose Windows_NT 10.0.14393
  12 verbose argv "C:\\Program Files\\nodejs\\node.exe" "C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "--proxy" "http://XXXXX" "--without-ssl" "--insecure" "-g" "install" "@angular/cli"
  13 verbose node v8.8.1
  14 verbose npm  v5.4.2
  15 error code E407
  16 error 407 Proxy Authorization Required: @angular/cli@latest
  17 verbose exit [ 1, true ]
  </code></pre>
  
  <p>Any idea what could have cause the issue? Thanks!</p>