Preparing for 3.4.0.rc2 release
Update README.md.

Remove the instructions to run the blacklight and hydra generators since the
sufia generator now runs both of these generators itself.
Merge pull request #221 from coblej/README-edit

Update README.md.
Update release instructions [ci skip]
Update releasing docs [ci skip]
Added pkg directory rake task [ci skip]
Update README to recommend removing turbolinks from application.js.
Merge pull request #224 from coblej/README-update

Update README to recommend removing turbolinks from application.js.