hastic-server docker redundant git

[jonyrock]

FROM node:8-alpine AS build

RUN apk add --no-cache git

# Note: context starts in the directory above (see docker-compose file)
COPY .git /var/www/.git
COPY server /var/www/server

We already have a webpack-building-stage-git-info and it should be enough.
@rozetko what do you think

[rozetko]

This part of Dockerfile is build stage. It's specified in the 1st line. This is what we do in this stage:

• copy all the necessary files from the repo to container (including .git)
• build server
• keep the artifacts (dist/) for the next stage

Everything else is removed as soon as the Docker image is built

[jonyrock]

so we decided with @rozetko internally that we will extract necessary from build variables like we do in webpack.

[jonyrock]

btw, it's a bit related https://github.com/hastic/hastic-server/issues/910