Highlight ints

[fordhurley]

Broke this off from #19 so that I could resolve the conflicts and try the custom scope name. Seems to work well for me. I have the following in my ~/.atom/styles.less to make ints stand out really well:

atom-text-editor::shadow .constant.numeric.integer.glsl {
  color: red;
}

Without the custom style, it continues to look the same as before.