build: remove apps package-locks from git

Author: CaerusKaru

.gitignore

@@ -24,3 +24,7 @@ npm-debug.log
 testem.log
 /.chrome
 !/test/karma.conf.js
+
+src/apps/universal-app/package-lock.json
+src/apps/demo-app/package-lock.json
+src/apps/hello-world/package-lock.json