ansi-wl-pprint-0.6.7.1 broken with ghc 7.10.1-rc3

[peti]

Citing from http://hydra.cryp.to/build/626491/nixlog/2/raw:

ext/PrettyPrint/ANSI/Leijen.hs:312:24:
    Ambiguous occurrence ‘<$>’
    It could refer to either ‘Text.PrettyPrint.ANSI.Leijen.<$>’,
                             defined at Text/PrettyPrint/ANSI/Leijen.hs:372:3
                          or ‘Prelude.<$>’,
                             imported from ‘Prelude’ at Text/PrettyPrint/ANSI/Leijen.hs:76:8-35
                             (and originally defined in ‘Data.Functor’)

[bergey]

Fixed in #11