Update .gitattributes (#1188)

* Update .gitattributes

* Update .gitattributes

Co-authored-by: Dries Vints <dries@vints.io>

Author: ankurk91

.gitattributes

@@ -16,6 +16,7 @@ public/*.js binary
 .editorconfig export-ignore
 .styleci.yml export-ignore
 CHANGELOG.md export-ignore
+package-lock.json export-ignore
 phpunit.xml.dist export-ignore
 RELEASE.md export-ignore
 UPGRADE.md export-ignore