Postgres 9.3
Fixes redis conf.

Wget writes nothing to stdout, Redis config files were therefore empty.
Updates redis versions.

I removed 2.4 since it's no more available on redis.io.
Removes useless redis.conf files.
More rubies
Merge jdk and jruby versions
No needed gcc for jruby
Do not change RAILS_ENV if it is already set.
Merge pull request #14 from ianschenck/rails_env_no_clobber

Do not change RAILS_ENV if it is already set.
Merge pull request #13 from Bugagazavr/master

Fix rubies 2.1.X and Add jruby
Merge pull request #9 from ctavan/postgres-9.3

Postgres 9.3
Merge pull request #11 from BertrandBordage/master

Fixes Redis configuration & updates Redis releases.