Update the version of bookbinder.
Update the version of bookbinder.

Signed-off-by: Matthew Boedicker <bd646ec310948bf2f36146b5501a0018bf548d0d@pivotallabs.com>

bridgetkromhout/docs-book-cloudfoundry,shalako/docs-book-cloudfoundry,shalako/docs-book-cloudfoundry,bridgetkromhout/docs-book-cloudfoundry,shalako/docs-book-cloudfoundry,cloudfoundry/docs-book-cloudfoundry,swisscom/docs-appcloud-book,Frazer-Anderson/test,cloudfoundry/docs-book-cloudfoundry,cwest/docs-book-cloudfoundry,swisscom/docs-appcloud-book,Frazer-Anderson/test,cwest/docs-book-cloudfoundry,cwest/docs-book-cloudfoundry,Frazer-Anderson/test,cloudfoundry/docs-book-cloudfoundry,cwest/docs-book-cloudfoundry,cloudfoundry/docs-book-cloudfoundry,bridgetkromhout/docs-book-cloudfoundry,bridgetkromhout/docs-book-cloudfoundry,shalako/docs-book-cloudfoundry,swisscom/docs-appcloud-book,swisscom/docs-appcloud-book