Simple connection, through docker

Update Dockerfile to include peewee and psql support
Connection with peewee
Connection with docker environment variable
Connection with a specific file containing string
Adaptation of peewee connection

peewee connection now use a config dict
peewee connection is now deferred to the start of the application, this avoid
multiple connections and allow strict workflow of DB initialisation
Add tests for /
Models creation
Add tests for db models

    Simple insertion and linking tests, those tests are disabled on the CI
    (integration tests)
Enum field

    Implement an enum field for postgres, adapt the model in consequence
Now use blueprint for loading part of the app

    See: https://exploreflask.com/blueprints.html for informations
    Blueprints bring a better architecture in flask applications
Add pylint support

Correct errors of linting in addition of pylint integration
Merge pull request #11 from RulzUrLife/pylint

Add pylint support
Merge pull request #10 from RulzUrLife/blueprint

Now use blueprint for loading part of the app
Merge pull request #9 from RulzUrLife/model_creation

Model creation