Deprecation warning for timestamps and Activerecord

[wikimatze]

Simple create a migration and run the migration:

padrino rake db:migrate
WARN: Unresolved specs during Gem::Specification.reset:
      activesupport (>= 3.1)
      tilt (< 3, >= 1.3)
WARN: Clearing out unresolved specs.
Please report a bug if this causes problems.
=> Executing Rake db:migrate ...
WARNING! In Padrino >= 0.14.0 cli command `padrino rake` will NOT add
'./lib' folder to $LOAD_PATH. Please alter your `require` calls accordingly
if you depend on this behavior.
  DEBUG -  ActiveRecord::SchemaMigration Load (0.1ms)  SELECT "schema_migrations".* FROM "schema_migrations"
   INFO -  Migrating to CreatePosts (2)
  DEBUG -   (0.0ms)  begin transaction
== 2 CreatePosts: migrating ===================================================
-- create_table(:posts)
DEPRECATION WARNING: `#timestamps` was called without specifying an option for `null`. In Rails 5, this behavior will change to `null: false`. You should manually specify `null: true` to prevent the behavior of your existing migrations from changing. (called from block in up at /tmp/sample_admin_slim_error/db/migrate/002_create_posts.rb:6)

Should we just add null: true in migrations with timestamps? I got rid of the warning by turning

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.string :name
      t.text :body
      t.timestamps
    end
  end

  def self.down
    drop_table :posts
  end
end

Into

class CreatePosts < ActiveRecord::Migration
  def self.up
    create_table :posts do |t|
      t.string :name
      t.text :body
      t.timestamps null: false
    end
  end

  def self.down
    drop_table :posts
  end
end

What's your opinion? If it's a yes, I try to implement it. You can read more about it under http://juanitofatas.com/2015/01/28/rails-5-timestamps/

[ujifgc]

If it's about changing padrino-gen, I think we should add :null => false as it's the new default.

[wikimatze]

Okay, I'll prepare the pull-request (to get more familiar in working more with the source-code and flow).