Simplify docker, shrink production image size!

[epugh]

Description

Motivation and Context

How Has This Been Tested?

Screenshots or GIFs (if appropriate):

Types of changes

• [] Bug fix (non-breaking change which fixes an issue)
• [] Improvement (non-breaking change which improves existing functionality)
• [] New feature (non-breaking change which adds new functionality)
• [] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [] My code follows the code style of this project.
• [] My change requires a change to the documentation.
• [] I have updated the documentation accordingly.
• [] I have read the CONTRIBUTING document.
• [] I have added tests to cover my changes.
• [] All new and existing tests passed.

[epugh]

By only copying over directories INTO the prod image I go from 2.42 GB to 1.83 GB.

With buster-slim and apt-get install mariadb-server libmariadbclient-dev mariadb-client mysql-common ruby-mysql2 libmariadbd-dev build-essential patch ruby-dev zlib1g-dev liblzma-dev gnupg I get down to 1.75GB in size.

[epugh]

@worleydl in a brand new version of Quepid, i ran into the tmp/pids issue too, so this PR is needed!

14:02:58 web.1 | bundler: failed to load command: puma (/usr/local/bundle/bin/puma)
14:02:58 web.1 | Errno::ENOENT: No such file or directory @ rb_sysopen - tmp/pids/server.pid
14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/launcher.rb:247:in write' 14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/launcher.rb:247:in write_pid'
14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/launcher.rb:111:in write_state' 14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/cluster.rb:398:in run'
14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/launcher.rb:181:in run' 14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/lib/puma/cli.rb:80:in run'
14:02:58 web.1 | /usr/local/bundle/gems/puma-5.4.0/bin/puma:10:in <top (required)>' 14:02:58 worker.1 | 2021-09-18T14:02:58.896Z pid=9 tid=6fd INFO: See LICENSE and the LGPL-3.0 for licensing details. 14:02:58 web.1 | /usr/local/bundle/bin/puma:23:in load'

[epugh]

So, this PR dropped the size by a GB!

➜ quepid git:(simplify_docker) docker images | grep quepid
o19s/quepid 6.8.0-practice 377d3bcb847d 17 minutes ago 1.48GB
o19s/quepid latest 377d3bcb847d 17 minutes ago 1.48GB
quepid_app latest 91050fe950ac 46 minutes ago 1.44GB
o19s/quepid 6.7.0 16bb81fe58af 4 weeks ago 2.42GB