Build failure with GHC 8

[snoyberg]

> /tmp/stackage-build8$ stack unpack highjson-0.2.0.2
Unpacked highjson-0.2.0.2 to /tmp/stackage-build8/highjson-0.2.0.2/
> /tmp/stackage-build8/highjson-0.2.0.2$ runghc -clear-package-db -global-package-db -package-db=/home/stackage/work/builds/nightly/pkgdb Setup configure --package-db=clear --package-db=global --package-db=/home/stackage/work/builds/nightly/pkgdb --libdir=/home/stackage/work/builds/nightly/lib --bindir=/home/stackage/work/builds/nightly/bin --datadir=/home/stackage/work/builds/nightly/share --libexecdir=/home/stackage/work/builds/nightly/libexec --sysconfdir=/home/stackage/work/builds/nightly/etc --docdir=/home/stackage/work/builds/nightly/doc/highjson-0.2.0.2 --htmldir=/home/stackage/work/builds/nightly/doc/highjson-0.2.0.2 --haddockdir=/home/stackage/work/builds/nightly/doc/highjson-0.2.0.2 --flags=
Configuring highjson-0.2.0.2...
> /tmp/stackage-build8/highjson-0.2.0.2$ runghc -clear-package-db -global-package-db -package-db=/home/stackage/work/builds/nightly/pkgdb Setup build
Building highjson-0.2.0.2...
Preprocessing library highjson-0.2.0.2...

src/Data/Json/Parser.hs:8:14: warning:
    -XOverlappingInstances is deprecated: instead use per-instance pragmas OVERLAPPING/OVERLAPPABLE/OVERLAPS
[1 of 3] Compiling Data.Json.Serialiser ( src/Data/Json/Serialiser.hs, dist/build/Data/Json/Serialiser.o )
[2 of 3] Compiling Data.Json.Parser ( src/Data/Json/Parser.hs, dist/build/Data/Json/Parser.o )

src/Data/Json/Parser.hs:265:11: error:
    Not in scope: type variable ‘m’

src/Data/Json/Parser.hs:265:60: error:
    Not in scope: type variable ‘m’

[agrafix]

Fixed in 0.3.0.0