Use real VCardStorage in socialprovider.spec.js

[dborkan]

Currently the socialprovider.spec.js tests mock out VCardStorage in a way that doesn't accurately reflect it's real behavior, e.g. getUser is not implemented, updateProperty doesn't result in an onClientState event, etc.

We should try to use the real VCardStrorage class in socialprovider.spec.js, and just mock out freedom['core.storage'] so that save and load are both no-ops.