code: func (g *Gitlab) ProjectDeployKey(id, keyId string) (*SshKey, *ResponseMeta, error) {
  	u := g.ResourceUrl(ProjectDeployKeyApiPath, map[string]string{
  		":id":     id,
  		":key_id": keyId,
  	})
  
  	var deployKey *SshKey
  
  	contents, meta, err := g.buildAndExecRequest("GET", u.String(), nil)
  	if err == nil {
  		err = json.Unmarshal(contents, &deployKey)
  	}
  
  	return deployKey, meta, err
  }
docs: /*
  Get single project deploy key.
  
      GET /projects/:id/keys/:key_id
  
  Parameters:
  
      id    The ID of a project
      keyId The ID of a key
  
  */