Fixed `ProjectThemeFactory.slug` unique generation.
Fixed `ProjectThemeFactory.slug` unique generation.

jfterpstra/bluebottle,onepercentclub/bluebottle,onepercentclub/bluebottle,jfterpstra/bluebottle,onepercentclub/bluebottle,onepercentclub/bluebottle,jfterpstra/bluebottle,onepercentclub/bluebottle,jfterpstra/bluebottle