DOC: added glpk removal to changelog.
DOC: added glpk removal to changelog.

amueller/pystruct,d-mittal/pystruct,pystruct/pystruct,amueller/pystruct,pystruct/pystruct,massmutual/pystruct,d-mittal/pystruct,wattlebird/pystruct,massmutual/pystruct,wattlebird/pystruct