Add new version '1.9.9.5.4' and '3.1.0-free'

Author: tangrufus

internal/wordfencetest/version_test.go

@@ -39,6 +39,7 @@ var invalidWordFenceVersions = []string{ //nolint:gochecknoglobals
 	"1.9.9.5.1",
 	"1.9.9.5.2",
 	"1.9.9.5.3",
+	"1.9.9.5.4",
 	"1.9.9.7.7",
 	"1.dec.2012",
 	"13-07-2019",
@@ -67,6 +68,7 @@ var invalidWordFenceVersions = []string{ //nolint:gochecknoglobals
 	"25.04010101-WP6.8",
 	"25.07010000-WP6.8.1-JB5.11.5",
 	"3.0 (Beta r7)",
+	"3.1.0-free",
 	"3.1.0.1.1",
 	"3.1.1.4.2",
 	"3.1.37.11.L",