title: How to adjust gutter in Bootstrap 3 grid system?
body: <p>The new Bootstrap 3 grid system is great. It's more powerful for responsive design at all screen sizes, and much easier for nested.</p>
  
  <p>But I have one issue I could not figure out. How do I add precise gap between the columns? Say I have container 960px, 3 columns at 310px and 2 gutters at 15px in between 3 columns. How do I do that?</p>