feat(loggin): disable logging by default so unit tests are not full of logging

pkg/services/sqlstore/migrations/migrations_test.go

@@ -6,7 +6,6 @@ import (
 	"github.com/go-xorm/xorm"
 	. "github.com/grafana/grafana/pkg/services/sqlstore/migrator"
 	"github.com/grafana/grafana/pkg/services/sqlstore/sqlutil"
-	"github.com/inconshreveable/log15"
 
 	. "github.com/smartystreets/goconvey/convey"
 )
@@ -29,7 +28,6 @@ func TestMigrations(t *testing.T) {
 			sqlutil.CleanDB(x)
 
 			mg := NewMigrator(x)
-			mg.Logger.SetHandler(log15.DiscardHandler())
 			AddMigrations(mg)
 
 			err = mg.Start()