Support base-4.8

[pharpend]

Trying to build this library with the newest version of GHC, this error pops up:

Resolving dependencies...
Configuring github-0.13.1...
Building github-0.13.1...
Failed to install github-0.13.1
Build log ( /home/pete/.cabal/logs/github-0.13.1.log ):
Configuring github-0.13.1...
Building github-0.13.1...
Preprocessing library github-0.13.1...
[ 1 of 31] Compiling Github.Repos.Webhooks.Validate ( Github/Repos/Webhooks/Validate.hs, dist/build/Github/Repos/Webhooks/Validate.o )

Github/Repos/Webhooks/Validate.hs:10:1: Warning:
    The import of ‘Control.Applicative’ is redundant
      except perhaps to import instances from ‘Control.Applicative’
    To import instances alone, use: import Control.Applicative()
[ 2 of 31] Compiling Github.Data.Definitions ( Github/Data/Definitions.hs, dist/build/Github/Data/Definitions.o )
[ 3 of 31] Compiling Github.Data      ( Github/Data.hs, dist/build/Github/Data.o )

Github/Data.hs:23:20:
    Ambiguous occurrence ‘defaultTimeLocale’
    It could refer to either ‘Data.Time.defaultTimeLocale’,
                             imported from ‘Data.Time’ at Github/Data.hs:9:1-16
                             (and originally defined in ‘time-1.5.0.1:Data.Time.Format.Locale’)
                          or ‘System.Locale.defaultTimeLocale’,
                             imported from ‘System.Locale’ at Github/Data.hs:14:23-39
cabal: Error: some packages failed to install:
github-0.13.1 failed during the building phase. The exception was:
ExitFailure 1

I believe this is due to an incompatibility with the newest version of base.

[hdgarrood]

Yes - defaultTimeLocale is now re-exported by Data.Time in the latest version. I think the easiest fix would be to use an explicit import list when importing from either module, and to always import defaultTimeLocale from System.Locale (so that it works on base < 4.8 too).

[pharpend]

I opened up a PR with a fix for base-4.8. I'm not familiar with CPP, so I'll leave the backwards compatibility stuff to someone else.

[pharpend]

Ohhh okay, I see what you mean. That was the first thing I tried, actually. It didn't work, because GHC doesn't realize the type from Data.Time is the same as the one from System.Locale.