Add method to update endpoint permissions for all pipelines

[beandrad]

So that all pipelines can be granted or denied access to
service endpoints.

Issue: #82

Example of use:

        // Create a client to interact with the Pipelines area
	pipelineClient := pipelines.NewClient(ctx, connection)
	if err != nil {
		log.Fatal(err)
	}
	resource_id := "9948edhu-b56d-4890-b0a6-0a980b1d8904"
	project := "testProject"
	authorized := true
	args := pipelines.UpdateEndpointPermissionsArgs{
		PermissionsParameters: &pipelines.PipelineResourcePermissions{
			Resource:     &pipelines.Resource{Id: &resource_id, Type: nil},
			AllPipelines: &pipelines.ResourcePermissions{Authorized: &authorized},
			Pipelines:    nil,
		},
		Project: &project,
	}
	permissionResponse, err := pipelineClient.UpdateEndpointPermissions(ctx, args)
	if err != nil {
		log.Fatal(err)
	}
	log.Printf("%v", *permissionResponse.AllPipelines.Authorized)

[tedchamb]

These are autogenerated files. They should not be hand edited. In order to add methods new clients will need to be generated.

[beandrad]

Thanks for looking into it @tedchamb. I'm not sure how to autogenerate the pipelines client; I was thinking of using Autorest and https://github.com/MicrosoftDocs/vsts-rest-api-specs/tree/master/specification, but I cannot find the corresponding configuration file in the repo.

[tedchamb]

@goflores, the clients are generated with the internal tool genclient. Ping me and I can help you as this means we will need to create a new major version.

[tedchamb]

Added in #87