Publish missing more_info_phone_number.
Fix "more info" tests for the contact presenter.

The test was expecting the presented values on the
`more_info_email_address` and `more_info_phone_number` fields to equal
the value on the model; this isn't the intended behaviour of the
presenter, as it passes these fields through Govspeak, but was passing
in the tests because these values weren't being set in the factory, and
so were defaulting to `nil`, which the Govspeak helper maps to `nil`.
Merge pull request #158 from alphagov/more_info_phone

Publish missing more_info_phone_number to content_store.