Log Message:
devel/hs-mono-traversable: update to mono-traversable-1.0.21.0

## 1.0.21.0

* Support for vector 0.13.2.0, adding instances for \ 
[`Data.Vector.Strict`](https://hackage.haskell.org/package/vector-0.13.2.0/docs/Data-Vector-Strict.html) \ 
data structure.
  [#244](https://github.com/snoyberg/mono-traversable/issues/244)

## 1.0.20.0

* Added instances for \ 
[`Reverse`](https://hackage.haskell.org/package/transformers-0.6.1.1/docs/Data-Functor-Reverse.html#t:Reverse) \ 
data structure.

## 1.0.19.1

* Removed 'highly experimental' warning haddock comment from Data.Containers.

## 1.0.19.0

* Added `filterWithKey` to `IsMap`.
  [#232](https://github.com/snoyberg/mono-traversable/pull/232)

## 1.0.18.0

* Added MonoPointed instance for text Builder
  [#225](https://github.com/snoyberg/mono-traversable/pull/225)