title: md-button size (angular material)
body: <p>I'm very new to angular-material and I'm using some <code>md-button</code> directives. As I'm coming from Bootstrap world, I'm searching for a way to have different sizes for <code>md-button</code>s. Something like <code>btn-xs</code> and <code>btn-sm</code> classes in Bootstrap.</p>
  
  <p>I created a class <code>md-button-xs</code> and tried to set size of button using this class with no success. I even tried to resize the button using developer options in Google Chrome but that didn't work too.</p>
  
  <p>How can I have different sizes for <code>md-button</code> and other Angular Material components?</p>