fix(stateDirectives): call update route state on page load

[maksad]

The latest PR #2363 removed a line from stateDirectives.js. This creates an issue. More precisely, when the page is loaded the update() function is not called the way it is expected.
Let me clarify this on an example:
Lets assume that we have an abstract state private. The private state has children states: index and settings. With routes #/private and #/settings.
And we have a navbar:

<ul>
  <li ui-sref-active="{'active': 'private'}"  class="parent">Private</li>
  <ul>
    <li>
      <a ui-sref="private.index">main</a>
    </li>
    <li>
      <a ui-sref="private.settings">settings</a>
    </li>
  </ul>
</ul>

Here we assume that every time we are in the index and settings ui-router should append class .active to .parent element. But in fact it never appends it on page load. It only appends it when the user clicks <a ui-sref="private.index">main</a> or <a ui-sref="private.settings">settings</a> links. Thats because the update is never called on page load. This PR solves the issue.

[christopherthielen]

Thanks for the PR! I merged #2447 because it also has a test.