Add copy for metadata choices to drug-device-alerts

This adjusts the format of the metadata for the signup choices so each choice
can contain more information
Remove duplicate extra copy.

This extra copy ("email alert subscription") is added by `finder-frontend` as
it's common to all email subscriptions.

Don't add it here.
Merge pull request #83 from alphagov/copy-metadata-for-signup

Add copy for metadata choices to drug-device-alerts
Increase timeout when using the email alert API to create lists

This can take longer than the default timeout resulting in the rake task
failing. If we up it to 30 we don't get timeout errors.
Merge pull request #85 from alphagov/increase-email-timeout-for-rake-task

Increase timeout when using the email alert API to create lists
Use format instead of slug for email lists

Previously we were using the finder’s slug to set the format of an
email subscription list. This was incorrect as there is differences
between the slugs and formats. (underscores/hyphens, plural/singular
and in the case of drug safety updates completely different)

This commit adds the formats to the metadata json files, and updated
the email list creator to use them instead of slugs.
Merge pull request #86 from alphagov/use-format-for-email-lists

Use format instead of slug for email lists
Make alert types plural

Similar to 5a107b7373cdc4e8fdf923b62b21d71027098016, there was a
mismatch between specialist publisher and what we specify here. Alert
types are plural, so update it here.
Merge pull request #87 from alphagov/alert-types-are-plural

Make alert types plural