Description:

Generates a new model. Pass the model name, either CamelCased or
under_scored, and an optional list of attribute pairs as arguments.

Attribute pairs are field:type arguments specifying the
model's attributes. Timestamps are added by default, so you don't have to
specify them by hand as 'created_at:datetime updated_at:datetime'.

As a special case, specifying 'password:digest' will generate a
password_digest field of string type, and configure your generated model and
tests for use with Active Model has_secure_password (assuming the default ORM
and test framework are being used).

You don't have to think up every attribute up front, but it helps to
sketch out a few so you can start working with the model immediately.

This generator invokes your configured ORM and test framework, which
defaults to Active Record and TestUnit.

Finally, if --parent option is given, it's used as superclass of the
created model. This allows you create Single Table Inheritance models.

If you pass a namespaced model name (e.g. admin/account or Admin::Account)
then the generator will create a module with a table_name_prefix method
to prefix the model's table name with the module name (e.g. admin_accounts)

Available field types:

Just after the field name you can specify a type like text or boolean.
It will generate the column with the associated SQL type. For instance:

    `bin/rails generate model post title:string body:text`

will generate a title column with a varchar type and a body column with a text
type. If no type is specified the string type will be used by default.
You can use the following types:

    integer
    primary_key
    decimal
    float
    boolean
    binary
    string
    text
    date
    time
    datetime

You can also consider `references` as a kind of type. For instance, if you run:

    `bin/rails generate model photo title:string album:references`

It will generate an `album_id` column. You should generate these kinds of fields when
you will use a `belongs_to` association, for instance. `references` also supports
polymorphism, you can enable polymorphism like this:

    `bin/rails generate model product supplier:references{polymorphic}`

For integer, string, text and binary fields, an integer in curly braces will
be set as the limit:

    `bin/rails generate model user pseudo:string{30}`

For decimal, two integers separated by a comma in curly braces will be used
for precision and scale:

    `bin/rails generate model product 'price:decimal{10,2}'`

You can add a `:uniq` or `:index` suffix for unique or standard indexes
respectively:

    `bin/rails generate model user pseudo:string:uniq`
    `bin/rails generate model user pseudo:string:index`

You can combine any single curly brace option with the index options:

    `bin/rails generate model user username:string{30}:uniq`
    `bin/rails generate model product supplier:references{polymorphic}:index`

If you require a `password_digest` string column for use with
has_secure_password, you can specify `password:digest`:

    `bin/rails generate model user password:digest`

If you require a `token` string column for use with
has_secure_token, you can specify `auth_token:token`:

    `bin/rails generate model user auth_token:token`

Examples:

`bin/rails generate model account`

    For Active Record and TestUnit it creates:

        Model:      app/models/account.rb
        Test:       test/models/account_test.rb
        Fixtures:   test/fixtures/accounts.yml
        Migration:  db/migrate/XXX_create_accounts.rb

`bin/rails generate model post title:string body:text published:boolean`

    Creates a Post model with a string title, text body, and published flag.

`bin/rails generate model admin/account`

    For Active Record and TestUnit it creates:

        Module:     app/models/admin.rb
        Model:      app/models/admin/account.rb
        Test:       test/models/admin/account_test.rb
        Fixtures:   test/fixtures/admin/accounts.yml
        Migration:  db/migrate/XXX_create_admin_accounts.rb