Remove "dot" dependence

[luismulinari]

I think that "dot" dependence is not good for future contributions and project maintenance.

We have gh-pages and we can use the "viz.js" to render graph without "dot".

I've created a gh-pages with this approach. You can see here an example.

If do you agree, I can send a pull request (if gh-pages branch exists).

[gaearon]

Maybe make it as a Node build step? I’d like this to load without a megabyte of JS.

[luismulinari]

You have a point.

Probably make a Node build step will be better.

[gaearon]

I'm happy to accept a PR doing this as a node build step. Closing as I personally don't plan to work on this.