Minimal docker environment setup

[bitmaybewise]

Given the idea of a minimal setup, and how pervasive Docker has become, I thought of adding an optional dockerized environment support.

It's super easy to get started with a dockerized environment:

$ docker-compose build
Building test
[+] Building 2.6s (11/11) FINISHED
 => [internal] load build definition from Dockerfile                                                                                                                                                   0.0s
 => => transferring dockerfile: 284B                                                                                                                                                                   0.0s
 => [internal] load .dockerignore                                                                                                                                                                      0.0s
 => => transferring context: 2B                                                                                                                                                                        0.0s
 => [internal] load metadata for docker.io/library/ruby:3.0                                                                                                                                            2.4s
 => [base 1/6] FROM docker.io/library/ruby:3.0@sha256:34bb95c8eefc62aaa1c83a13ab0e32215f929eecd3d21c3768be807d17fb2734                                                                                 0.0s
 => [internal] load build context                                                                                                                                                                      0.0s
 => => transferring context: 4.07kB                                                                                                                                                                    0.0s
 => CACHED [base 2/6] RUN bundle config --global frozen 1                                                                                                                                              0.0s
 => CACHED [base 3/6] WORKDIR /opt/app                                                                                                                                                                 0.0s
 => CACHED [base 4/6] COPY Gemfile Gemfile.lock ./                                                                                                                                                     0.0s
 => CACHED [base 5/6] RUN bundle install                                                                                                                                                               0.0s
 => [base 6/6] COPY . .                                                                                                                                                                                0.0s
 => exporting to image                                                                                                                                                                                 0.0s
 => => exporting layers                                                                                                                                                                                0.0s
 => => writing image sha256:0fc0249791f142d097c10b00d127ea712aa2ced3e42f164bbc49e0c9e1bccae6                                                                                                           0.0s
 => => naming to docker.io/library/minimal-ruby-project_test

$ docker-compose run test
Creating minimal-ruby-project_test_run ... done
Run options: --seed 64744

# Running:

.

Finished in 0.000952s, 1050.9202 runs/s, 1050.9202 assertions/s.

1 runs, 1 assertions, 0 failures, 0 errors, 0 skips