package.json: Move nyc exclude into nyc property
package.json: Move nyc exclude into nyc property

Listing all excludes in a property of package.json makes them consistent
across nyc invocations and more easily introspectable.

Signed-off-by: Kevin Locke <ffb4761cba839470133bee36aeb139f58d7dbaa9@kevinlocke.name>

kevinoid/appveyor-status,kevinoid/appveyor-status,kevinoid/appveyor-status