Remove useless patch for readline on 14.04

This patch was made to handle some compilations errors with ruby 2.1.1
and ubuntu 14.04 (readline 6.3), but this patch has only removed
readline library with an invalid configure option.
I removed this invalid patch, and the readline issue has been fixed
with ruby 2.1.2
Fix tests and specs with data bag ruby-2.1.2
Fix integration test for rubies_attributes

It’s should be only tested with Ubuntu version < 14.04 or readline < 6.3
Bump to v0.3.1