Fix instructions for running the Ruby installation scripts in the -cu…

…stomizable variant

Upgrade to Ruby 2.1.7, Ruby 2.2.3, JRuby 0.9.4.0, Node.js 0.12.9

Release 0.9.17

Note 0.9.16 release date

Run 'docker tag' in the tag_latest task with -f

Fix setuid bit on /usr/bin/sudo, bump version to 0.9.14.

Merge pull request phusion#54 from Yggdrasil/patch-1

Fix typo in Readme

Base on baseimage-docker 0.9.13

Note release date for 0.9.11

Fix typo