Dialyzer Fix

My first checkout of master returned the following dialyzer errors:

```
chef_user.erl:135: The call chef_user:new_record(OrgId::any(),AuthzId::any(),{_,{'null','null','null'}}) breaks the contract (object_id(),object_id(),ejson_term() | {ejson_term(),{binary(),binary(),binary()}}) -> #chef_user{}
chef_user.erl:325: Type specification chef_user:update_from_ejson(#chef_user{},ejson_term()) -> #chef_user{} is a supertype of the success typing: chef_user:update_from_ejson(#chef_user{pubkey_version::'undefined' | 0 | 1},{[any()]}) -> #chef_user{pubkey_version::'undefined' | 0 | 1}
```

The first was an easy spec change.

The second was just dialyzer being dialyzer, but we're able to give that one a free pass by removing `-Wunderspec`