Failing to build distributive-0.5.2 with GHC 7.8.4

[markandrus]

I'm temporarily removing GHC 7.8.4 from .travis.yml and twilio.cabal since it's causing build errors. Hopefully these can be resolved and we can add it back.

$ cabal build
...
Downloading distributive-0.5.2...
[1 of 1] Compiling Main             ( /tmp/distributive-0.5.2-2498/distributive-0.5.2/Setup.lhs, /tmp/distributive-0.5.2-2498/distributive-0.5.2/dist/setup/Main.o )
Linking /tmp/distributive-0.5.2-2498/distributive-0.5.2/dist/setup/setup ...
/opt/ghc/7.8.4/lib/ghc-7.8.4/unix-2.7.0.1/libHSunix-2.7.0.1.a(HsUnix.o): In function `__hsunix_ptsname':
(.text+0x120): multiple definition of `__hsunix_ptsname'
/home/travis/.cabal/lib/x86_64-linux-ghc-7.8.4/unix-2.7.2.1/libHSunix-2.7.2.1.a(HsUnix.o):HsUnix.c:(.text+0x20): first defined here
/opt/ghc/7.8.4/lib/ghc-7.8.4/unix-2.7.0.1/libHSunix-2.7.0.1.a(HsUnix.o): In function `__hsunix_grantpt':
(.text+0x130): multiple definition of `__hsunix_grantpt'
/home/travis/.cabal/lib/x86_64-linux-ghc-7.8.4/unix-2.7.2.1/libHSunix-2.7.2.1.a(HsUnix.o):HsUnix.c:(.text+0x30): first defined here
/opt/ghc/7.8.4/lib/ghc-7.8.4/unix-2.7.0.1/libHSunix-2.7.0.1.a(HsUnix.o): In function `__hsunix_unlockpt':
(.text+0x140): multiple definition of `__hsunix_unlockpt'
/home/travis/.cabal/lib/x86_64-linux-ghc-7.8.4/unix-2.7.2.1/libHSunix-2.7.2.1.a(HsUnix.o):HsUnix.c:(.text+0x40): first defined here
/opt/ghc/7.8.4/lib/ghc-7.8.4/unix-2.7.0.1/libHSunix-2.7.0.1.a(HsUnix.o): In function `__hsunix_push_module':
(.text+0x150): multiple definition of `__hsunix_push_module'
/home/travis/.cabal/lib/x86_64-linux-ghc-7.8.4/unix-2.7.2.1/libHSunix-2.7.2.1.a(HsUnix.o):HsUnix.c:(.text+0x50): first defined here
collect2: ld returned 1 exit status
Failed to install distributive-0.5.2
...
cabal: Error: some packages failed to install:
bifunctors-5.2.1 depends on distributive-0.5.2 which failed to install.
comonad-5.0.1 depends on distributive-0.5.2 which failed to install.
distributive-0.5.2 failed during the configure step. The exception was:
ExitFailure 1
free-4.12.4 depends on distributive-0.5.2 which failed to install.
profunctors-5.2 depends on distributive-0.5.2 which failed to install.
semigroupoids-5.2 depends on distributive-0.5.2 which failed to install.