update BEAST 2 citation #858
update BEAST 2 citation #858

Anaphory/beast2,Anaphory/beast2,CompEvol/beast2,tgvaughan/beast2,Anaphory/beast2,tgvaughan/beast2,Anaphory/beast2,CompEvol/beast2,CompEvol/beast2,tgvaughan/beast2,CompEvol/beast2,tgvaughan/beast2