Add pipeline schedule API (#351)

README.md

@@ -52,7 +52,7 @@ to add new and/or missing endpoints. Currently the following services are suppor
 - [x] Page Domains
 - [x] Pipelines
 - [x] Pipeline Triggers
-- [ ] Pipeline Schedules
+- [x] Pipeline Schedules
 - [x] Projects (including setting Webhooks)
 - [ ] Project Access Requests
 - [x] Project Members

gitlab.go

@@ -287,6 +287,7 @@ type Client struct {
 	NotificationSettings *NotificationSettingsService
 	PagesDomains         *PagesDomainsService
 	Pipelines            *PipelinesService
+	PipelineSchedules    *PipelineSchedulesService
 	PipelineTriggers     *PipelineTriggersService
 	Projects             *ProjectsService
 	ProjectMembers       *ProjectMembersService
@@ -373,6 +374,7 @@ func newClient(httpClient *http.Client, tokenType tokenType, token string) *Clie
 	c.NotificationSettings = &NotificationSettingsService{client: c}
 	c.PagesDomains = &PagesDomainsService{client: c}
 	c.Pipelines = &PipelinesService{client: c}
+	c.PipelineSchedules = &PipelineSchedulesService{client: c}
 	c.PipelineTriggers = &PipelineTriggersService{client: c}
 	c.Projects = &ProjectsService{client: c}
 	c.ProjectMembers = &ProjectMembersService{client: c}