Revert "Disable failing test on Travis"

This reverts commit 2170943ae6
and commit 623c9afa84.

hugolib/page_test.go

@@ -18,7 +18,6 @@ import (
 	"fmt"
 	"html/template"
 	"os"
-	"runtime"
 
 	"path/filepath"
 	"reflect"
@@ -912,9 +911,6 @@ func TestPageWithDate(t *testing.T) {
 }
 
 func TestPageWithLastmodFromGitInfo(t *testing.T) {
-	if runtime.GOOS != "windows" && os.Getenv("CI") != "" {
-		t.Skip()
-	}
 	assrt := require.New(t)
 
 	// We need to use the OS fs for this.