Update Navbar to follow Bootstrap 3 examples

Update Navbar to follow Bootstrap 3 examples at
http://getbootstrap.com/getting-started/#examples-navbars.

- Switch dropdown caret to <span> instead of <b>

- Add navbar-default class to outer div

- Add button type and collapsed class to button for responsive navbar
Remove navbar-inner div from Navbar
Wrap button and brand around navbar-header class
Merge pull request #6 from suhasgaddam/updatingToExamples

Update to follow Bootstrap 3 navbar examples