Update docker base image and move to Python 3.6 + Django 2.0

[backmari]

Short description of the changes:

First step in migrating Live Data Server to newer versions of Python and Django.

Information about changes between Django 1.9 and 2.0:
https://docs.djangoproject.com/en/dev/releases/1.10/#deprecated-features-1-10
https://docs.djangoproject.com/en/dev/releases/2.0/#backwards-incompatible-changes-in-2-0

Check list for the pull request

• I have read the [CONTRIBUTING]
• I have read the [CODE_OF_CONDUCT]
• I have added tests for my changes
• I have updated the documentation accordingly

Check list for the reviewer

• I have read the [CONTRIBUTING]
• I have verified the proposed changes
• best software practices
  • all internal functions have an underbar, as is python standard
  • clearly named variables (better to be verbose in variable names)
  • code comments explaining the intent of code blocks
• All the tests are passing
• The documentation is up to date
• code comments added when explaining intent

Manual test for the reviewer

Define environment variables (name, user, password can be set to anything):

export DATABASE_NAME=***
export DATABASE_USER=***
export DATABASE_PASS=***
export DATABASE_HOST=db  # name of the db docker service
export DATABASE_PORT=5432
export LIVE_PLOT_SECRET_KEY=""

Start the containers:

make local/docker/up

and when the containers are up run the unit test:

DJANGO_SUPERUSER_USERNAME=<same as DATABASE_USER> DJANGO_SUPERUSER_PASSWORD=<same as DATABASE_PASS> pytest tests

References

Story 4767: [LiveDataServer] Deploy containerized Live Data Server and test with WebMon test environment

[peterfpeterson]

The way that our conda deploy is setup uses conda_bootstrap.sh

[jmborr]

looks 👌