Start moving auth-based decorators to ligoauth app

gracedb/ligoauth/decorators.py

+from django.conf import settings
+from django.contrib.auth import REDIRECT_FIELD_NAME
+from django.contrib.auth.decorators import user_passes_test
+from django.core.exceptions import PermissionDenied
+import logging
+
+logger = logging.getLogger(__name__)
+
+
+def group_required(group_name, login_url=None, raise_exception=False):
+    def check_groups(user):
+        in_group = user.groups.filter(name=group_name).exists()
+        if in_group:
+            return True
+
+        if raise_exception:
+            raise PermissionDenied
+        return False
+    return user_passes_test(check_groups, login_url=login_url)
+
+
+def internal_user_required(function=None, raise_exception=True, **kwargs):
+    actual_decorator = group_required(settings.LVC_GROUP, 
+        raise_exception=raise_exception, **kwargs)
+    if function:
+        return actual_decorator(function)
+    return actual_decorator