This patch adds an .npmrc file for the jenkins user on our pypi slave.
Note that actually publishing to npm will only work on trusty or later.
This patch requires a manual step, where a member of infra-root registers
the openstackci user on npm, and injects the password into hiera.
Note that npm credentials require a user, password, and URL, some of which
are specified in site.pp.
Change-Id: I13fa91500a7b189e5fb6e915968727e8c1f2a1f4
efc8402cbd