ACTOR_REGEX

gafaelfawr.constants.ACTOR_REGEX = '^[a-z0-9](?:[a-z0-9]|-[a-z0-9])*[a-z](?:[a-z0-9]|-[a-z0-9])*$|^<[a-z]+>$'

Regex matching all valid actors (including <bootstrap>).