Fix Rakefile load in production deployment
Fix Rakefile load in production deployment

When deployed, the test dependencies aren't installed. To allow the
`xsd:all` task to be run correctly, we need to rescue the LoadError and
proceed anyway.

ausaccessfed/saml-service,ausaccessfed/saml-service,ausaccessfed/saml-service,ausaccessfed/saml-service