degrees

Easily handle temperature values in rust. You can compare and combine temps safely without manually converting to and from different units. For example you can subtract 10degC from 86degF. The crate will handle the conversions internally and give you a result in the initial unit.

```rust use degrees:Temp;

let value = Temp::F(86.) - Temp::C(10.); // Temp::F(36.0) ```

This also means you can safely compare temperatures in two different units

```rust use degrees:Temp;

let value = Temp::F(86.) == Temp::C(30.); // true ```