ghc-lens-4.13-2.6

- Update to version 4.13 revision 0 with cabal2obs.

- update to 4.13
  * Pattern synonyms
  * Moved foldMapBy and foldBy into reflection 2.1
  * Added traverseByOf, sequenceByOf.
  * Reexported traverseBy and sequenceBy from reflection 2.1.
  * Modified the signatures of alaf and auf to work with a Functor rather than
    a Profunctor and rather drastically generalized them.
  * Removed Control.Lens.Internal.Getter.coerce in favor of the upstream phantom
    combinator in contravariant 1.3+
  * Renamed coerced to phantasm to get it out of the way.
  * Added Wrapped instance for Down

- initial commit