Build failure with GHC-7.8

Hi Francesco, I came here randomly via https://github.com/haskell-infra/hackage-trustees/issues/347 .

I found no information which GHCs utf8-light build with. Typically, this would be detailed in:

• The bounds on base.
• The tested-with field. (https://github.com/haskell-CI/haskell-ci uses this to generate CI on github.)
• The changelog.
• The build matrix of the CI.

Currently, none of these alternatives gave me the information. So I tried a few GHCs and discovered that build fails on 7.8 (because of the usual Prelude incompatibility, I suspect):

$ cabal build -w ghc-7.8.4
...
Building library for utf8-light-0.4.3..
...
[2 of 2] Compiling Codec.Binary.UTF8.Light ( ... )

src/Codec/Binary/UTF8/Light.hs:90:16:
    Not in scope: type constructor or class ‘Word’
    Perhaps you meant ‘Word8’ (imported from GHC.Word)

The simplest fix is to revise to base >= 4.8 && < 5.

Cheers, Andreas