Merge branch 'master' into 'dev'

.gitlab-ci.yml

Dockerfile

backend/Procfile

backend/runtime.txt

backend/secfit/requirements.txt

backend/secfit/secfit/djangoHeroku.py

backend/secfit/secfit/settings.py

frontend/Procfile

frontend/www/exercise.html

frontend/www/login.html

frontend/www/logout.html

frontend/www/mycoach.html

frontend/www/register.html

frontend/www/scripts/navbar.js

frontend/www/scripts/scripts.js

frontend/www/scripts/statistics.js

frontend/www/scripts/workouts.js

frontend/www/statistics.html

frontend/www/styles/style.css

frontend/www/workout.html