Add commands to hide all solutions for testing purposes

server/core/management/commands/hidesolutions.py

@@ -0,0 +1,12 @@
+from django.core.management import BaseCommand
+
+from books.models import Module
+
+
+class Command(BaseCommand):
+    def handle(self, *args, **options):
+        self.stdout.write("Hiding solutions")
+        for module in Module.objects.all():
+            self.stdout.write("Hiding solutions in module {}.".format(module.title))
+            module.solutions_enabled_by.clear()
+        self.stdout.write("Hiding done")