One-Stack-Vec
===

## Overview
OneStackVec is simple data structure which contains any number of items.
It does not heap allocation until there is one or zero item.

## How to use
```rust
// Initialize
let mut items = OneStackVec::new();

// Adding
items.add(42);

// Getting
assert_eq!(Some(&42), items.get(0));

// Removing
assert_eq!(Some(&42), items.remove(0));
assert_eq!(None, items.get(0));
```