integer_primary_key migration issue

[totaltrash]

Describe the bug

The migrator generates a non-incrementing, nullable field for integer_primary_key.

To Reproduce

An attribute defined as:

integer_primary_key :id

generates:

add(:id, :integer, null: true, default: nil, primary_key: true)

Expected behavior

add(:id, :serial, null: false, primary_key: true)

[zachdaniel]

This is currently tracked in #32, thanks for reporting it in further detail!