'staging' database is not configured. Available: ["defaults", "production", "writeable"] (ActiveRecord::AdapterNotSpecified)

defaults: &defaults
  adapter: mysql2
  host: eu-west-1.rds.amazonaws.com
  pool: 10
  reconnect: true
  encoding: utf8
  database: Project_database

production:
  <<: *defaults
  username: Username
  password: Password
  port: 3306

writeable:
  <<: *defaults
  username: Username
  password: Passowrd
  port: 3306

staging:
  <<: *defaults
  username: Username
  password: Password
  port: 3306

default: &default
  adapter: postgresql
  encoding: unicode
  host: localhost