EmailPGPPublicKeyField does not use the correct mixin #77
Description
As defined in https://github.com/incuna/django-pgcrypto-fields/blob/master/pgcrypto/fields.py#L41 EmailPGPPublicKeyField uses the PGPSymmetricKeyFieldMixin mixin instead of the PGPPublicKeyFieldMixin one.