allow multiple platforms for build

Author: goya

CHEATSHEET.md

@@ -62,7 +62,7 @@ pgb.getApp(id) // get single app
 pgb.getAppLog(id, platform) // get build log for a single platform
 pgb.downloadApp(id, platform, [path]) // save app to optional path
 pgb.pullApp(id) // pull new version from repo and trigger a build
-pgb.buildApp(id, [platform]) // build app, optionally by single platform
+pgb.buildApp(id, [platforms...]) // build app, optionally by specified platforms
 pgb.deleteApp(id) // delete app
 
 /* COLLABORATORS */