Stability Mechanism -- Implementation

[andrewvyrros]

• Implement function
• Include comments
• Write tests

(The title of this is not great, not sure what to call it. This is for make_base_stability(), the Measurement that calculates noisy counts via stability.)

[andrewvyrros]

Issue for proof is in #117.

[Shoeboxam]

The measurement itself is implemented. The output is a HashMap<K, C>, where K is the released category and C the noisy count for that category. We need a way to return hashmaps over FFI.

[andrewvyrros]

In the interest of granularity, let's call this done. I've opened #125 for the HashMap data loader.