message: serialization.Serializer: Remove now superfluous specialization for `DurationOpt`.
diff: @@ -598,38 +598,6 @@ namespace elle
  };
  };
  - template <>
  - struct Serialize<DurationOpt>
  - {
  - static
  - void
  - serialize(DurationOpt const& o,
  - elle::serialization::SerializerOut& s)
  - {
  - s._serialize_option(
  - bool(o),
  - [&]
  - {
  - Serializer::serialize_switch(s, elle::unconst(*o));
  - });
  - }
  -
  - static
  - DurationOpt
  - deserialize(elle::serialization::SerializerIn& s)
  - {
  - DurationOpt res;
  - s._serialize_option(
  - false,
  - [&]
  - {
  - res.emplace(Serializer::Details::deserialize<Duration>(
  - static_cast<SerializerIn&>(s), 42));
  - });
  - return res;
  - }
  - };
  -
  template <>
  struct Serialize<Time>
  {
  