Merge branch 'issue_1_horstmann' into 'develop'

add backgroud images

See merge request !3
2 jobs for develop in 2 minutes and 3 seconds (queued for 2 seconds)
Name Stage Failure
failed
run_test Test
$ yarn install --frozen-lockfile --silent --non-interactive
warning " > @babel/plugin-proposal-export-default-from@7.5.2" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "@babel/plugin-proposal-export-default-from > @babel/plugin-syntax-export-default-from@7.2.0" has unmet peer dependency "@babel/core@^7.0.0-0".
warning "react-scripts > @typescript-eslint/eslint-plugin@1.13.0" has incorrect peer dependency "eslint@^5.0.0".
warning "react-scripts > @typescript-eslint/parser@1.13.0" has incorrect peer dependency "eslint@^5.0.0".
warning "react-scripts > @typescript-eslint/eslint-plugin > tsutils@3.17.1" has unmet peer dependency "typescript@>=2.8.0 || >= 3.2.0-dev || >= 3.3.0-dev || >= 3.4.0-dev || >= 3.5.0-dev || >= 3.6.0-dev || >= 3.6.0-beta || >= 3.7.0-dev || >= 3.7.0-beta".
$ ln -s config.env.example config/test.env
ln: failed to create symbolic link 'config/test.env': No such file or directory
ERROR: Job failed: exit code 1