Avoid kvm in dockerImage builds

[enobayram]

By using copyToRoot instead of a generic runAsRoot.

Fixes #189

[enobayram]

$ docker load < $(nix build github:kadena-io/chainweb-data/enis/no-kvm-docker-build#chainweb-data-docker --no-link --print-out-paths)
trace: WARNING: 9.6.3 is out of date, consider using 9.6.4.
Loaded image: chainweb-data:latest

$ docker run -ti --rm chainweb-data:latest --help
chainweb-data - Processing and analysis of Chainweb data

Usage: chainweb-data (COMMAND | COMMAND | COMMAND 
                       (--dbstring ARG | [--dbhost ARG] [--dbport ARG] 
                         [--dbuser ARG] [--dbpass ARG] --dbname ARG) 
                       [--service-https] --service-host HOST 
                       [--service-port PORT] [--level ARG] 
                       [(-m|--migrate) | --ignore-schema-diff] 
                       [--migrations-folder PATH] 
                       [--extra-migrations-folder PATH])

Available options:
  --dbstring ARG           Postgres Connection String
  --dbhost ARG             Postgres DB hostname
...

[mbwmbw1337]

Confirmed to solve #189.