• Fix regression that prevented registering Go migrations that didn't have the corresponding files
  available in the filesystem. (#588)
  • If Go migrations have been registered globally, but there are no .go files in the filesystem,
    always include them.
  • If Go migrations have been registered, and there are .go files in the filesystem, only
    include those migrations. This was the original motivation behind #553.
  • If there are .go files in the filesystem but not registered, raise an error. This is to
    prevent accidentally adding valid looking Go migration files without explicitly registering
    them.