When running the container and building the examples, the following error occurs:
Error: EACCES: permission denied, open '/home/node/examples/browser/browser-webpack-example/bundle.js'
Commands used:
```
docker build -t orbit-db -f docker/Dockerfile . --no-cache
docker run -ti --rm orbit-db npm run build:examples
```
This commit introduces a Dockerfile for building Docker images of OrbitDB
base installations on node.js. It is based on official nodejs image, and
can also be used either as a base image for building new images for
projects that use OrbitDB, or as image for throwaway temporary containers.
