Automate payment at confirmation by taking billing info beforehand

[cheyenneweaver]

ToDo:
x Edit the payment page --> "Note: You will not be able to edit your apprenticeship until we've had a chance to approve it. Then any edits will need to be re-approved."
x update the maker confirm email to say "you've been charged"
x update the app_signup confirm email ("Righteous") to mention that we didn't charge you yet.
x add back a section into _confirm_form.html that says we'll charge you later
x pull the checkbox for confirm_fee into the new "Payment" area and tweak the wording (on the _form and _parent partials!!)
x we need to introduce a way for an apprentice to "decline" confirming the apprenticeship so that they don't get charged if they don't want to work together. I wrote it into the email here "You still have the chance to decline the apprenticeship", but we should add a link and text elsewhere. -- They can cancel the application; I updated the wording in the emails and added a link to the dashboard.
x add links to "update my billing info" in case someone wants to change this (put the credit card render back into the _confirm_form.html)
x move _confirm_form fields onto _form
x remove links and language around confirming after acceptance
x update app_signups_controller actions, remove payment_confirmation page
x add checks for failed apprentice payment

Random Issues:
x Daughter first_name/last_name/age field validations aren't working; allows you to submit but state transition fails. (created a validation group called "apply" and moved validations out of state machine)

• Error when accepting an apprenticeship (Cannot transition via "accept") -- can't repro?

Test:

• that this has not screwed up posting & signing up for workshops
• posting a second apprenticeship after we've got your payment info on file
• applying for a second apprenticeship after we've got your payment info on file
• rake task: 1. x (logic in app_signup.process_auto_payment), 2. logic in app_signup.auto_confirm_apprenticeship, 3. calling the rake task itself