Find a way to warn users about the changes to the specification hooks

[fabiopelosin]

from

Pod::Spec.new do |spec|
  def spec.pre_install(pod, target_definition)
    Dir.chdir(pod.root){ `sh make.sh` }
  end
end

to

Pod::Spec.new do |spec|
  spec.pre_install do |pod, target_definition|
    Dir.chdir(pod.root){ `sh make.sh` }
  end
end

/cc @alloy

[alloy]

BOOM!

class Spec
  def pre_install(pod, target_definition)
  end

  def singleton_method_added(method)
    if [:pre_install, :post_install].include?(method)
      warn "The use of `#{method}' by overriding the method is deprecated."
    end
  end
end

spec = Spec.new
def spec.pre_install(pod, target_definition); end

[fabiopelosin]

Awesome!