Merge branch '18-try-out-gitlab-s-static-code-analysis' into 'master'

Resolve "Try out Gitlab's static code analysis"

Closes #18

See merge request elixir/elixir-beacon!18
3 jobs for master in 3 minutes and 1 second (queued for 1 second)
Name Stage Failure
dependency_scanning Integration
[INFO] [gemnasium-python] [2020-07-13T14:27:57Z] ▶ Found project in /tmp/app/backend

[INFO] [gemnasium-python] [2020-07-13T14:27:57Z] ▶ Running analyzer
exit status 1
2020/07/13 14:28:02 Container exited with non zero status code
Uploading artifacts...
WARNING: gl-dependency-scanning-report.json: no matching files
ERROR: No files to upload
ERROR: Job failed: exit code 1