Add change_column to Rails/ReversibleMigration

[mattmccormick]

Is your feature request related to a problem? Please describe.

change_column is not on the list of the migration definitions supported by the change method. This is easy to miss as there are a couple change_column_* methods that are supported.

When trying to rollback a migration that uses change_column in the change method, the following error will be displayed and the rollback will fail:

StandardError: An error has occurred, this and all later migrations canceled:

This migration uses change_column, which is not automatically reversible.
To make the migration reversible you can either:
1. Define #up and #down methods in place of the #change method.
2. Use the #reversible method to define reversible behavior.

Describe the solution you'd like

Add change_column to the ReversibleMigration cop.

Describe alternatives you've considered

Trying to remember this instead :)

Additional context

none