Moved date available check to participant #3802

so that the check can be used by the reconsent scheduling rake task
First pass at rake task #3802

to schedule re-consents
specs for date_available #3802
Update based on feedback #3802

The Participant#date_available_for_informed_consent_event?
method should only take a Date (not either a Date or String) so
update this method and callers accordingly.

This date can be given by the user calling the rake task to
schedule reconsent events via highline.

In all places attempting to schedule a participant notify the
user of the progress or of any issues.
Merge pull request #157 from NUBIC/3802_reconsent_script

3802 reconsent script