title: Capybara & Bootstrap dropdown not able to select an option
body: <p>Here's the dropdown menu:</p>
  
  <pre><code>&lt;div class="btn-group bootstrap-select dropup open"&gt;
    &lt;button type="button" class="btn dropdown-toggle btn-default" data-toggle="dropdown" data-id="taggings_tag_id" title="Nothing selected" aria-expanded="true"&gt;
      &lt;span class="filter-option pull-left"&gt;Nothing selected&lt;/span&gt;&amp;nbsp;&lt;span class="bs-caret"&gt;&lt;span class="caret"&gt;&lt;/span&gt;&lt;/span&gt;
    &lt;/button&gt;
    &lt;div class="dropdown-menu open" style="max-height: 484px; overflow: hidden; min-height: 92px;"&gt;
      &lt;ul class="dropdown-menu inner" role="menu" style="max-height: 472px; overflow-y: auto; min-height: 80px;"&gt;
        &lt;li data-original-index="0" class="selected"&gt;
          &lt;a tabindex="0" class="" style="" data-tokens="null"&gt;
            &lt;span class="text"&gt;&lt;/span&gt;
            &lt;span class="glyphicon glyphicon-ok check-mark"&gt;
            &lt;/span&gt;
          &lt;/a&gt;
        &lt;/li&gt;
        &lt;li data-original-index="1"&gt;
          &lt;a tabindex="0" class="" style="" data-tokens="null"&gt;
            &lt;span class="text"&gt;Create Account&lt;/span&gt;
            &lt;span class="glyphicon glyphicon-ok check-mark"&gt;&lt;/span&gt;
          &lt;/a&gt;
        &lt;/li&gt;
      &lt;/ul&gt;
    &lt;/div&gt;
    &lt;select class="selectpicker" id="taggings_tag_id" name="taggings[tag_id]" tabindex="-98"&gt;
      &lt;option value=""&gt;&lt;/option&gt;
      &lt;option value="1"&gt;Create Account&lt;/option&gt;
    &lt;/select&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I'm trying to select that "Create Account" option from the dropdown. I can get capybara to click on the dropdown and expand the list, but I can't get it to select the correct option--resulting in a null value failure when it clicks on Add Tag. </p>
  
  <pre><code>it 'adds a tag' do
    page.find(:xpath, "//button[@title='Nothing selected']").click
    option=all("ul.dropdown-menu.inner &gt; li").last
    option.click
    find('input[value="Add Tag"]').trigger("click")
    expect(page).to have_content 'Create Account'
  end
  </code></pre>