Drop commons-lang dependency
Drop commons-lang dependency

yang-data-impl's test dependency on commons-lang is unused.

Change-Id: I46d543ede3190537ff9f9dacffa57a78e1e1f462
Signed-off-by: Stephen Kitt <c64219c0e25aff6572376b1dfbf7cf444494f5c6@redhat.com>

opendaylight/yangtools,opendaylight/yangtools