Add configuration/settings endpoints

[T-Dnzt]

Issue/Task Number: #502
closes #502

Overview

This PR adds two new endpoints to manage the configuration settings:

• /configuration.get
• /configuration.update

I decided to go with configuration.* instead of settings. simply because we already have a /settings.all endpoint that returns something in the shape of

%{
  minted_tokens: []
}

I didn't know how to reuse that and make it fit with the settings system, so using something like /configuration.* made more sense. Totally up for discussion if you guys have better ideas.

Changes

• Add count to the pagination object to know exactly how many records are being returned in the response (suggested by one of our mobile developers, a small change that makes it easier to parse a response and adds little overhead in the code).
• Add /configuration.get to retrieve the list of all settings. This actually returns a paginated, filterable and sortable list of settings. /configuration.all could be a better name to stay consistent.
• Add /configuration.update that takes a hash of settings update in the form of:

%{
  "setting_name_1": "setting_value_1",
  "setting_name_2": "setting_value_2",
}

And will return a list of insert results which can either be:

• an updated setting (configuration_setting type)
• an error changeset (error type)
• a configuration_setting_error (that would occur in case a setting key is not found)

To Do

• Update Swagger

[mederic-p]

list of configurations

[mederic-p]

Do we really need to have 2 different kind of error objects returned? If possible I'd stick with only error and try to remove configuration_setting_error

[unnawut]

+1

[unnawut]

Since we're using "configuration" now, should this be changed to ConfigurationSchema?

Also SettingResponse -> ConfigurationResponse a bit down below.

[T-Dnzt]

I wish it was just settings, but it was taken, so instead we send back a configuration composed of a set of settings, that's why you see both settings and configuration in the spec depending on the level.