bitbucket: add end points
bitbucket: add end points

Change-Id: I0dee5ae8d822ecf0bc873534fbbba5d0ec546c7b
Reviewed-on: https://go-review.googlesource.com/14664
Reviewed-by: Andrew Gerrand <395a7d33bec8475c9b83b7d440f141bcbd994aa5@golang.org>

danielkarch/oauth2,jboeuf/oauth2,dbmedialab/golang-oauth2,pengwynn/oauth2-1,paul-at-start/oauth2,drewwells/oauth2,golang/oauth2,awormuth/oauth2,hoysoft/oauth2