Circe: Add an fs2 module

[travisbrown]

This would probably look similar to circe-streaming but would use fs2 instead of iteratee.io.

[fsvehla]

Is there also interest in a version for Monix observables?

[fommil]

looks like I may have need of a Pipe[F, Byte, T] and (maybe) a Pipe[F, T, Byte] which would be constructed if there is an implicit (circe equivalent of) JsonReader[T] around. Or would it be better to provide Pipe[F, Byte, JsonValue] and then a separate Pipe[F, JsonValue, T]?

[fommil]

ah, looks like @n4to4 already did the latter! Pipe[F, Chunk[Byte], Json] (although I think fs2 may need to chunk up the bytes in that case)

[travisbrown]

This is now available in a separate repo in the circe org.