haskell on centos 6.5

Use justhub rather than version in epel repo.

Don't bother with the version of haskell-platform in epel repo. It is sufficiently out-of-date (circa 2010) that it can't update via cabal install cabal-install. Jump straight to using justhub.

Justhub example for centos 6.x:

# install the justhub yum repo:
sudo rpm -ivh http://sherkin.justhub.org/el6/RPMS/x86_64/justhub-release-2.0-4.0.el6.x86_64.rpm

# install single current haskell version into /usr/bin
yum install haskell

# update cabal
cabal update

# e.g. install some packages via cabal
cabal install haskell-src-exts

Now I can get back to coding for exercism.io. Come review my first haskell program.