Change signature#70

## Support exception handling in HTTP tasks If HTTP status indicates an error, Future will not fail. However, response status errors and exceptions such as connections can now be handled together by handling exceptions with validStatus and recover. Pickup will recover a Future that has received an abnormal status and failed. However, it does not pickup any failures other than receiving an anomaly value. ```scala http[GET](url) .map(???) .pickup .recover { case e => ??? } .recoverF { case e => Future.failed(???) } . recoverWith { case e => http[GET](url).run } ``` ## Added AutoDerive. By importing this, it is possible to auto-guess the top-level codec as well. We were able to guess the CaseClass and the codecs inside more than one level, but the top-level codecs had to be explicitly stated. ```scala object Codecs extends CodecDef { implicit val codec: MyID = CaseClassCodec.from[MyID] } object Main extends JsonTransform { import Codecs._ val result: Seq[MyID] = Nil val serialized: String = result // Seq[MyID]'s Codec was only automatically guessed by inheriting CodecDef. } ``` Import `AutoDerive._` from here onwards to guess all codecs is possible. ### Be careful with the implicit scope. AutoDerive will try to guess all the codecs except the scope that has priority over import scope. This may result in duplicate implicit codecs or the use of unintended codecs, depending on the implementation.