Pass OS Places API credentials from hieradata to Puppet class
Pass OS Places API credentials from hieradata to Puppet class

We were seeing in the logs on `locations_api` machines:

```
[47639b95-b57e-4355-8ec0-6cff48294285] {"exception_class":"OsPlacesApi::MissingOsPlacesApiCredentials","exception_message":"OsPlacesApi::MissingOsPlacesApiCredentials","stacktrace":["lib/os_places_api/access_token_manager.rb:6:in `initialize'","app/controllers/v1/locations_controller.rb:6:in `new'","app/controllers/v1/locations_controller.rb:6:in `index'"]}
```

We've defined the values already in govuk-secrets, but hadn't
done the work to pass the values to the class and declare them
as ENV variables (needed here:
https://github.com/alphagov/locations-api/blob/25e6788cd52f7a74a9a70ab467cde9d21a89fcd7/lib/os_places_api/access_token_manager.rb#L6-L9
)

Trello: https://trello.com/c/gPRVvLXh/2848-set-up-remaining-infrastructure-for-locations-api-5

alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet,alphagov/govuk-puppet