We are moving boldly on to QEMU 2.0 in the next release.  Some patches
written at a time where we assumed 1.8 would be the next version number
managed to sneak in.

s/1.8/2.0/ in qapi-schema.json

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>