We were using the dts rollup plugin when attempting to bundle our fork

of the Backbone types, but this plugin ends up rewriting those. This is

a problem for the particular setup in the Backbone types file. What we

really wanted to do was just copy it as-is.
This change does exactly that. We now use rollup-plugin-copy to just

simply copy anything in src/@types into lib, preserving it as-is.
This fixes issues with using Spina with TypeScript when using the built

package.

Built a package and consumed it successfully without typing issues.