fix microsoft#21252, add package-lock.json to npmignore (microsoft#21260)

HerringtonDarkholme · mhegazy · commit c11a3f4ff65a · 2018-01-18T10:23:25.000-08:00
diff --git a/.npmignore b/.npmignore
@@ -18,4 +18,5 @@ Jakefile.js
 .settings/
 .travis.yml
 .vscode/
-test.config
+test.config
+package-lock.json
