Bug 1022515 - Marketplace download suggestions still show up even if the app is installed

https://bugzilla.mozilla.org/show_bug.cgi?id=1022515
I'm only wondering if this should be done by the provider itself in https://github.com/mozilla-b2g/gaia/blob/master/apps/search/js/providers/marketplace.js#L46
instead of being the default behavior for all providers. your call! :+1: