/README/

##usersテーブル

Column	Type	Options
name	string	null: false, foreign_key: true
email	string	null: false, foreign_key: true
password	text	null: false, foreign_key: true

###Association has_many :messages has_many :groups, through: :groups_users

##groupsテーブル

Column	Type	Options
name	string	null: false, foreign_key: true

###Association has_many :messages has_many :users, through: :groups_users

##groups_usersテーブル

Column	Type	Options
user_id	integer	null: false, foreign_key: true
group_id	integer	null: false, foreign_key: true

###Association belongs_to :group belongs_to :user

###messagesテーブル

Column	Type	Options
body	text	null: false, foreign_key: true
image	string	foreign_key: true
user_id	integer	null: false, foreign_key: true
group_id	integer	null: false, foreign_key: true

###Association belongs_to :group belongs_to :user

This README would normally document whatever steps are necessary to get the application up and running.

Things you may want to cover:

• Ruby version

• System dependencies

• Configuration

• Database creation

• Database initialization

• How to run the test suite

• Services (job queues, cache servers, search engines, etc.)

• Deployment instructions

• ...