Add pkg-config dependency

matplotlib uses pkg-config to detect dependencies (freetype).
Merge pull request #288 from kajiglet/patch-1

Add pkg-config dependency to matplotlib
Update ansible package to use a release tarball instead of a git checkout
Update ruby to 2.1.2 -- latest stable
Merge pull request #289 from jcftang/wip-update-ansible-release-tarball

Update ansible package to use a release tarball instead of a git checkou...
Merge pull request #290 from jcftang/wip-update-ruby

Update ruby to 2.1.2 -- latest stable
initial add of saltstack