Support conditional execution of organized interactors

[hedgesky]

Fixes #128.
I've decided to create OrganizedInteractor class to hold organized interactors along with passed options. This class is also responsible to run interactors with regard of passed options. :if and :unless are currently supported; you could pass either a symbol or a proc.

[hedgesky]

I'd rather use keyword argument for within_organizer here, but currently gemspec is targeted to Ruby 2.0.

[temkin]

This is a very good feature! Why not merged yet?

[mikepence]

+1 huge missing part of organizers

[gustavomazzoni]

+1

[hedgesky]

Hi @laserlemon, I know it's been a while since this conversation was started and probably now this gem isn't in your list of priorities. I'm not going to ask you to invest a lot of your time, but maybe you could merge the PR?
It will help people who want to use the feature. At the same time, leaving it undocumented makes it kind of experimental and leaves you with possibility to change it in future if you'd like to.

[lfv89]

That is a really helpful feature.

@laserlemon do you think you will be able to review this PR anytime soon?

[iriscoopers]

+1 !

[fedefa]

+1!