Dockerfile with virtual env and multi-stage buiid

[northwestwitch]

Modified Dockerfile to:

• Execute the app from a virtual environment (fix #33)
• Build Dockerfile with multi-stage build

Test1 --> venv

Make sure the Dockefile works. Run:

• make setup
• make report
• Go to report: http://localhost:5000/report?sample_id=sample1&sample_id=sample2&sample_id=sample3

Test2 --> multi-stage build

• Build Dockerfile from master branch and build Dockerfile from this branch. The one from this branch should be built faster

[northwestwitch]

Test docker-compose (make commands): 🆗

[northwestwitch]

@dnil an easy review for when you have some time. No rush!

[dnil]

Yep, code looks good and runs just fine on a local docker:

[northwestwitch]

Thanks for the review!