Add edit_folders service permission

This is a temporary permission to allow some services to see and
edit folders before the feature is turned on for everyone.

migrations/versions/0239_add_edit_folder_permission.py

@@ -0,0 +1,22 @@
+"""
+
+Revision ID: 0239_add_edit_folder_permission
+Revises: 0238_add_validation_failed
+Create Date: 2018-09-03 11:24:58.773824
+
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = '0239_add_edit_folder_permission'
+down_revision = '0238_add_validation_failed'
+
+
+def upgrade():
+    op.execute("INSERT INTO service_permission_types VALUES ('edit_folders')")
+
+
+def downgrade():
+    op.execute("DELETE FROM service_permissions WHERE permission = 'edit_folders'")
+    op.execute("DELETE FROM service_permission_types WHERE name = 'edit_folders'")