Pin jsonschema version below 1.0.0.

The latest jsonschema version breaks the unit tests. This commit pins
the version to be less than the latest release.

Fixes bug 1132840

Change-Id: Ib4db4782f995cee179445ca11d2b6a7f13a6b457
Merge remote-tracking branch 'm_src_repo/webob-issue' into build-temp