[agda] Install agda on Mac OS

I’ve tried installing

cabal install Agda-2.3.2.1 

But got dependency errors.

cabal: cannot configure parallel-3.1.0.1. It requires deepseq ==1.1.*	

Installing an older version works:

cabal install Agda-2.3.0.1 

References

[1] http://wiki.portal.chalmers.se/agda/pmwiki.php?n=Main.MacOSX
[2] http://agda.orangesquash.org.uk/2012/November/14.html