Added info about boost to the readme
Added info about boost to the readme

Peilun-Li/dynet,cherryc/dynet,kamigaito/cnn,Abasyoni/dynet,cherryc/dynet,Abasyoni/dynet,Peilun-Li/dynet,kamigaito/cnn,cherryc/dynet,mitchellstern/dynet,mitchellstern/dynet,Abasyoni/dynet,Peilun-Li/dynet