Doctrine Migrations fail in MySQL 5.6+

[thecoolestguy]

When running the 'bin/console doctrine:migrations:migrate --env=prod' command when upgrading from an Ilios 2.x installation, some migrations fail because they attempt to change the structure of a column that is referenced in a previously-set FOREIGN KEY CONSTRAINT (see here: http://stackoverflow.com/questions/17015844/mysql-5-6-foreign-key-constraint-error-didnt-occur-in-5-5)

I've tried the the workaround suggested and dropped the FKC before altering the column and then recreating it after, and it works, but we need to change the migrations in several places. I will list this places in this issue as they are discovered.

[mtb3]

I encountered this issue in my environment with MySQL 5.6.

Dropping the FKC in the migrations per the commit mentioned above does work to solve this issue for me.

[thecoolestguy]

This is fixed in #1451