Place constants right after the includes

[Morriar]

So type_member and type_template are at the top.

I feel like having:

class Foo
  extend T::Generics

  def foo; end

  Elem = type_member

  SOME_OTHER_CONST = 42
end

is worse than having:

class Foo
  extend T::Generics

  Elem = type_member

  SOME_OTHER_CONST = 42

  def foo; end
end