Fix citation formatting that was a run-on line
Fix citation formatting that was a run-on line

The citation for the IEEE article was formatted as code. Sphinx displayed this as a very long line. This is now formatted as a block quote.
jhillairet/scikit-rf,jhillairet/scikit-rf,scikit-rf/scikit-rf,jhillairet/scikit-rf,scikit-rf/scikit-rf