Downgrade PZH WS Package.json, to fix issue in Express/Send deps.

The 'express' and 'send' modules are broken on npm, this forces
them to use a slightly older, working version.

Jira issue: WP-1097
Merge pull request #16 from jplyle/downgrade-express

Downgrade PZH WS Package.json, to fix issue in Express/Send deps.