This patch makes some optimizations in the result service's image;
- switch to `node:8.9-alpine`, which a smaller base image
- use `https://` for the registry
- use `COPY` instead of `ADD`, following best pracice
- cleanup npm cache, and combine steps to reduce image size
These changes bring down the image size from 248MB to 81.2MB
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>