upgrade to use testfixtures v3 (#11904)

* upgrade to use testfixtures v3

* simplify logic

* make vendor

* update per @lunny

* Update templates/repo/empty.tmpl

* Update templates/repo/empty.tmpl

Co-authored-by: Lauris BH <lauris@nix.lv>

vendor/github.com/mattn/go-sqlite3/sqlite3_opt_preupdate_omit.go

@@ -0,0 +1,21 @@
+// Copyright (C) 2019 G.J.R. Timmer <gjr.timmer@gmail.com>.
+// Copyright (C) 2018 segment.com <friends@segment.com>
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file.
+
+// +build !sqlite_preupdate_hook,cgo
+
+package sqlite3
+
+// RegisterPreUpdateHook sets the pre-update hook for a connection.
+//
+// The callback is passed a SQLitePreUpdateData struct with the data for
+// the update, as well as methods for fetching copies of impacted data.
+//
+// If there is an existing update hook for this connection, it will be
+// removed. If callback is nil the existing hook (if any) will be removed
+// without creating a new one.
+func (c *SQLiteConn) RegisterPreUpdateHook(callback func(SQLitePreUpdateData)) {
+	// NOOP
+}