Update Cargo.toml

This fixes

```
The package `rustc-serialize v0.3.24` currently triggers the following future incompatibility lints:
> warning: impl method assumes more implied bounds than the corresponding trait method
>     --> /home/at/.cargo/registry/src/index.crates.io-6f17d22bba15001f/rustc-serialize-0.3.24/src/serialize.rs:1155:41
>      |
> 1155 |     fn decode<D: Decoder>(d: &mut D) -> Result<Cow<'static, T>, D::Error> {
>      |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace this type to make the impl signature compatible: `Result<Cow<'a, T>, <D as serialize::Decoder>::Error>`
>      |
>      = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
>      = note: for more information, see issue #105572 <rust-lang/rust#105572>
>      = note: `#[allow(implied_bounds_entailment)]` on by default
>
```

Cargo.toml

@@ -9,5 +9,5 @@ license = "MIT"
 
 [dependencies]
 lazy_static = "1"
-num = "0.1"
-regex = "0.2"
+num = "0.4"
+regex = "1"