use ecstatic instead of connect

this changes 2 lines of code + allows me to have links like `http://blockplot.dev/world` instead of only `http://blockplot.dev/world.html` as `ecstatic` has a `defaultExt` option: https://github.com/jesusabdullah/node-ecstatic/blob/master/lib/ecstatic.js#L74-L96

it would be best to make the ecstatic options externally configurable but I wanted to keep this simple