Add "Slash Slack Commands" integration to API
Description
The current Gitlab API exposes many useful ways to configure groups and repositories, including "integrations" or "services". Recently the "Slack Slash Commands" integration was added to Gitlab, but it appears to not yet have made it into the API. This appears to be just be a mistake as all other integrations are configurable via the API. We should add the "Slack Slash Commands" integration to the API.
Proposal
Implement API endpoints for configuring the Slack Slash Commands integration for a project. It should expose the following endpoints (cribbed from https://docs.gitlab.com/ce/api/services.html):
Create/Edit Slack Slash Command service
Set Slack Slash Command for a project.
PUT /projects/:id/services/slack-slash-commands
Parameters:
-
token
(required) - A string representing the Slack token belonging to this slash command
Delete Slack Slash Command service
Delete Slack Slash Command service for a project.
DELETE /projects/:id/services/slack-slash-commands
Get Slack Slash Command service settings
Get Slack Slash Command service settings for a project.
GET /projects/:id/services/slack-slash-commands
The relevant documentation must also be updated (https://docs.gitlab.com/ce/api/services.html).