1.5.4

* Fix fatal error reporting with "type" (draft v3), "oneOf" (draft v4), "not"
  (draft v4): they were swallowed silently.

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>
Announce 1.5.4, 1.4.8

Signed-off-by: Francis Galiegue <fgaliegue@gmail.com>