TODOs from #51

[ryanmrichard]

PR #51 adds a stub RAM class. This issue is meant to track all of the stubs introduced in that PR.

• Actually get memory size
• Actually make RAM instance and give to ResourceSet
• RAM::gather
• RAM::reduce
• RuntimeView::my_resource_view
• RuntimeView::count
• RuntimeView::equal_range
• RuntimeView::gather
• RuntimeView::reduce