title: Unable to install npm package hosted on a private registry with jspm
body: <p>I am trying to get jspm working with a private npm registry (which mirrors the public registry).</p>
  
  <p>I used the endpoint config tool to configure jspm from .npmrc appears to work successfully</p>
  
  <pre><code>GAVINJ:jspm-test gavinj$ jspm endpoint config npm
  npmrc found, would you like to use these settings? [yes]:
  npm registry [http://registry.npm.ourcompanyname.net/]:
  Would you like to test these credentials? [yes]:
  ok   npm authentication is working successfully.
  ok   Endpoint npm configured successfully.
  </code></pre>
  
  <p>Installing our package 'michelangelo' (which is not in the public npm registry) works just fine</p>
  
  <pre><code>GAVINJ:jspm-test gavinj$ npm install michelangelo
  highstock-release@2.0.4 node_modules/highstock-release
  jquery@2.1.3 node_modules/jquery
  d3@3.5.5 node_modules/d3
  lodash@3.3.1 node_modules/lodash
  michelangelo@2.0.1641 node_modules/michelangelo
  </code></pre>
  
  <p>Attempting to install the same npm package via jspm does not work.</p>
  
  <pre><code>GAVINJ:jspm-test gavinj$ jspm install michelangelo=npm:michelangelo
       Looking up npm:michelangelo
  
  err  Repo michelangelo not found!
  
  warn Installation changes not saved.
  </code></pre>
  
  <p>Attempting to install lodash via jspm works perfectly</p>
  
  <pre><code>GAVINJ:jspm-test gavinj$ jspm install lodash=npm:lodash
       Looking up npm:lodash
       Updating registry cache...
       Looking up github:jspm/nodelibs-process
       Looking up npm:process
  ok   Up to date - lodash as npm:lodash@^3.3.1 (3.3.1)
  ok   Install tree has no forks.
  
  ok   Install complete.
  </code></pre>
  
  <p>Here's what my jspm config file looks like</p>
  
  <pre><code>{
    "registry": "jspm",
    "endpoints": {
      "github": {
        "timeouts": {
          "lookups": 60
        },
        "handler": "jspm-github",
        "remote": "https://github.jspm.io"
      },
      "npm": {
        "timeouts": {
          "lookups": 60
        },
        "registry": "http://registry.npm.ourcompanyname.net/",
        "remote": "https://npm.jspm.io",
        "auth": "PRIVATE_HERE_BUT_SAME_AS_NPMRC_FILE",
        "handler": "jspm-npm"
      },
      "jspm": {
        "timeouts": {
          "lookups": 60
        },
        "handler": "jspm-registry",
        "remote": "https://registry.jspm.io"
      }
    }
  }
  </code></pre>
  
  <p>Any idea why I am unable to install the npm pacakge via jspm?  Or, any advice on how I could track down the problem?</p>