Corrects macro that generates create method of forms

[Xosmond]

Fixes #311

[edwardloveall]

Hey @Xosmond! We've moved and renamed LuckyRecord to Avram. We decided to move it instead of using GitHub's rename option so that current code that relies on lucky_record would continue to work and a project must opt-in to the new shard. However, a big bummer is we can't move PRs.

If you are still interested in this change, would you be able to rebase onto Avram? If not don't worry about it. We can eventually rebase it for you. Thanks 😄! Let us know if you have any questions.

[Xosmond]

@edwardloveall Hey sure, will do. But actually I wanted to know your opinion and also @paulcsmith about two ways for creating records.

This PR would fix the bug but also allow to create records like this (having username is a regular field and password andpassword_confirmation are virtual fields):

RegistrationForm.create! username: "hello", password: "my password", password_confirmation: "my password"

But only fixing virtual parameters bug, would need us to write it like this:

RegistrationForm.create! params: { "username" => "hello" }, password: "my password", password_confirmation: "my password"

So which do you think would be better?

[paulcsmith]

I love that first version. Looks more type safe and I think it’s more intuitive! 👍

[Xosmond]

@paulcsmith Ok i will move this and create the tests but I see NEEDS_ON_INITIALIZE, NEEDS_ON_CREATE and NEEDS_ON_UPDATE are not actually used, do you have a reason for these constants? I ask this because they can generate possible bugs.