Circle.yml config for elixir/phoenix/docker app

Build Environment
1

Hello, guys

I am a beginning in the circle ci usage. so I need some help to correct configure my circle.yml
I am using docker and docker compose in my app:

docker-compose

web:
  build: .
  ports:
    - "4000:4000"
  command: mix phoenix.server
  environment:
    - MIX_ENV=dev
    - PORT=4000
  volumes:
    - .:/app
  links:
    - db
db:
  image: postgres
  environment:
    - POSTGRES_USER=postgres
    - POSTGRES_PASSWORD=postgres
    - POSTGRES_HOST=db
    
deps:
  image: api_web
  command: mix deps.get
  environment:
    - MIX_ENV=dev
  volumes_from:
    - web

compile:
  image: api_web
  command: mix deps.compile
  environment:
    - MIX_ENV=dev
  volumes_from:
    - web

test:
  image: api_web
  command: mix test
  environment:
    - MIX_ENV=test
  volumes_from:
    - web
  links:
    - db

Dockerfile

FROM elixir:latest

MAINTAINER Cristiano <cristiano.codelab@gmail.com>

RUN mix local.hex --force

RUN mix archive.install --force https://github.com/phoenixframework/archives/raw/master/phoenix_new.ez

RUN mix local.rebar --force

WORKDIR /app

All that i need is just a simple circle.yml fille.
I tried a lot of times to do it so I gave up and delete it. I did not know about this forum.