Adopt SummerCMS v0.1.1 admin features

Datepickers on native time.Time / lagoon.Date fields, file uploads on
materials, readings and class sessions managed from the course form
(course_id made nullable).

controllers/api/dashboard.go

@@ -1,6 +1,7 @@
 package api
 
 import (
+	"git.golem15.com/golem15/summercms/modules/lagoon"
 	"net/http"
 
 	"git.golem15.com/jakub/sm-bm-plugin/models"
@@ -46,7 +47,7 @@ func (h *Handlers) Dashboard(w http.ResponseWriter, r *http.Request) {
 	}
 	out.UpcomingDeadlines = newDeadlinesJSON(deadlines)
 
-	day := today(h.now()).Format(models.DateLayout)
+	day := lagoon.DateOf(today(h.now())).String()
 	var err error
 	if out.CurrentMeeting, err = meetingWhere(db, "starts_on <= ? AND ends_on >= ?", day, day); err != nil {
 		writeOpaque500(w)