Pin the "yum" cookbook to the 2.4.4 version

Prevent `could not find recipe epel for cookbook yum` errors on Centos.

See: https://github.com/opscode-cookbooks/yum#notes
[VAGRANT] Install Java 7 for all defined VMs
[TEST] Fix test for the Nginx proxy failing on Elasticsearch 1.0
Added the `-d` switch to init script for Elasticsearch 1.x

Closes #185
[VAGRANT] Refactored the Chef installation shell provisioner in Vagrantfile
[VAGRANT] Remove VMs: precise32, lucid64, lucid32

Leaving only Ubuntu Precise and Centos 6