circleciの設定がうまくいかない

前提・実現したいこと

現在ポートフォリオの作成をしている最中なのですが、circleciにてrspecとrubocopのテストが
通ったらherokuデプロイが行われるように設定したいのですがうまくいきません。
ちなみにローカル環境ではrubocop,rspec,deploy全てうまくいきます。
具体的にできていないこととしては、postgres:9.6がうまく立ち上がらないことです。
エラー内容下記に記載させていただきます。

発生している問題・エラーメッセージ

Error: Database is uninitialized and superuser password is not specified.
       You must specify POSTGRES_PASSWORD to a non-empty value for the
       superuser. For example, "-e POSTGRES_PASSWORD=password" on "docker run".

       You may also use "POSTGRES_HOST_AUTH_METHOD=trust" to allow all
       connections without a password. This is *not* recommended.

       See PostgreSQL documentation about "trust":
       https://www.postgresql.org/docs/current/auth-trust.html

Exited with code 1
CircleCI received exit code 1

#!/bin/bash -eo pipefail
bundle exec rails db:create RAILS_ENV=test
could not translate host name "db" to address: Name or service not known
Couldn't create 'searching_outlet_test' database. Please check your configuration.
rails aborted!
ActiveRecord::ConnectionNotEstablished: could not translate host name "db" to address: Name or service not known

該当のソースコード

version: 2
jobs:
  rspec:
    docker:
      - image: circleci/ruby:2.7.4-node-browsers
        environment:
          RAILS_ENV: test
          DB_HOST: 127.0.0.1
          DB_USERNAME: postgres
          DB_PASSWORD: password
      - image: circleci/postgres:9.6
        environment:
          POSTGRES_DATABASE: searching_outlet_test
          POSTGRES_USER: postgres
          POSTGRES_PASSWORD: password
    working_directory: ~/searching_outlet
    steps:
      - checkout
      - restore_cache:
          keys:
            - v1-dependencies-{{ checksum "Gemfile.lock" }}-{{ checksum "yarn.lock" }}
            - v1-dependencies-
      - run:
          name: update bundler
          command: |
            gem update --system
            gem install bundler:2.1.4
      - run: bundle install --jobs=4 --retry=3 --path vendor/bundle
      - save_cache:
          key: v1-dependencies-{{ checksum "Gemfile.lock" }}-{{ checksum "yarn.lock" }}
          paths:
            - ./vendor/bundle
      - run: bundle exec rails db:create RAILS_ENV=test
      - run: bundle exec rails db:schema:load RAILS_ENV=test
      - run:
          name: yarn Install
          command: yarn install
      - run: bundle exec bin/webpack
      - run:
          name: RSpec
          command: bundle exec rspec
  rubocop:
    docker:
      - image: circleci/ruby:2.7.4-node-browsers
        environment:
          RAILS_ENV: test
          DB_HOST: 127.0.0.1
          DB_USERNAME: postgres
          DB_PASSWORD: password
      - image: circleci/postgres:9.6
        environment:
          POSTGRES_DATABASE: searching_outlet_test
          POSTGRES_USER: postgres
          POSTGRES_ROOT_PASSWORD: password
    working_directory: ~/searching_outlet
    steps:
      - checkout
      - restore_cache:
          keys:
            - v1-dependencies-{{ checksum "Gemfile.lock" }}-{{ checksum "yarn.lock" }}
            - v1-dependencies-
      - run:
          name: update bundler
          command: |
            gem update --system
            gem install bundler:2.1.4
      - run: bundle install --jobs=4 --retry=3 --path vendor/bundle
      - save_cache:
          key: v1-dependencies-{{ checksum "Gemfile.lock" }}-{{ checksum "yarn.lock" }}
          paths:
            - ./vendor/bundle
      - run: bundle exec rails db:create RAILS_ENV=test
      - run: bundle exec rails db:schema:load RAILS_ENV=test
      - run:
          name: RuboCop
          command: bundle exec rubocop

workflows:
  version: 2
  rspec_and_rubocop_workflow:
    jobs:
      - rspec
      - rubocop

version: '3'
services:
  db:
    image: postgres
    ports:
      - '5432:5432'
    volumes:
      - postgresql-data:/var/lib/postgresql/data
    environment:
      - POSTGRES_PASSWORD=password
  web:
    build:
      context: .
      dockerfile: Dockerfile
    command: bundle exec rails s -p 3000 -b '0.0.0.0'
    tty: true
    stdin_open: true
    depends_on:
      - db
    ports:
      - "3000:3000"
    volumes:
      - .:/searching_outlet
volumes:
  postgresql-data:
    driver: local

# SQLite. Versions 3.8.0 and up are supported.
#   gem install sqlite3
#
#   Ensure the SQLite 3 gem is defined in your Gemfile
#   gem 'sqlite3'
#
default: &default
  adapter: postgresql
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000
  encoding: unicode
  host: db
  username: postgres
  password: password

development:
  <<: *default
  database: searching_outlet_development

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: searching_outlet_test

production:
  <<: *default
  password: <%= ENV['SEARCHING_OUTLET_DATABASE_PASSWORD'] %>