backuptarget: add default at provisioning time (again)

we clear the db in the tests. the tests run the setup again and again.
so, it's easier to add default values in provision time instead of
migration.

src/backuptargets.js

@@ -5,6 +5,7 @@ exports = module.exports = {
     getPrimary,
     list,
     add,
+    addDefault,
     del,
 
     setConfig,
@@ -516,6 +517,22 @@ async function add(data, auditSource) {
     return id;
 }
 
+async function addDefault(auditSource) {
+    assert.strictEqual(typeof auditSource, 'object');
+
+    debug('addDefault: adding default backup target');
+    const defaultBackupTarget = {
+        name: 'Default',
+        provider: 'filesystem',
+        config: { backupDir: paths.DEFAULT_BACKUP_DIR },
+        retention: { keepWithinSecs: 2 * 24 * 60 * 60 },
+        schedule: '00 00 23 * * *',
+        format: 'tgz'
+    };
+    defaultBackupTarget.id = await add(defaultBackupTarget, auditSource);
+    await setPrimary(defaultBackupTarget, auditSource);
+}
+
 // creates a backup target object that is not in the database
 async function createPseudo(data) {
     assert.strictEqual(typeof data, 'object');