Aeson 2 support

[theophile-scrive]

Hi! my organisation is depending on this library and we would like to provide a patch to support Aeson 2. Would you be open to this? :)

[erikd]

I am not a maintainer of this project, but yes, having support for aeson >= 2.0 would be a huge plus.

[andreabedini]

AFAIK this only needs a revision, most of IOG's repos do allow-newer: ekg:aeson.
edit: no, I am wrong. ekg depends on ekg-json which does not compile with aeson>=2.0. The reason it works at IOG is because we patched it.

[theophile-scrive]

@tibbe hopeful ping? :)