message: Update mapping types
diff: #### primitive types (`T`)
  -| Cassandra | Rust |
  +| Cassandra | Rust | Feature
  |-----------|--------------|
  -| tinyint | i8 |
  -| smallint | i16 |
  -| int | i32 |
  -| bigint | i64 |
  -| ascii | String |
  -| text | String |
  -| varchar | String |
  -| boolean | bool |
  -| time | i64 |
  -| timestamp | i64 |
  -| float | f32 |
  -| double | f64 |
  -| uuid | [Uuid](https://doc.rust-lang.org/uuid/uuid/struct.Uuid.html) |
  +| tinyint | i8 | v4, v5 |
  +| smallint | i16 | v4, v5 |
  +| int | i32 | all |
  +| bigint | i64 | all |
  +| ascii | String | all |
  +| text | String | all |
  +| varchar | String | all |
  +| boolean | bool | all |
  +| time | i64 | all |
  +| timestamp | i64 | all |
  +| float | f32 | all |
  +| double | f64 | all |
  +| uuid | [Uuid](https://doc.rust-lang.org/uuid/uuid/struct.Uuid.html) | all |
  #### complex types
  | Cassandra | Rust + CDRS |
  |-----------|-------------|
  -| list | [List](https://docs.rs/cdrs/1.0.0-beta.2/cdrs/types/list/struct.List.html) -> Vec<T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L297) |
  -| set | [List](https://docs.rs/cdrs/1.0.0-beta.2/cdrs/types/list/struct.List.html) -> Vec<T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L297)|
  -| map | [Map](https://docs.rs/cdrs/1.0.0-beta.2/cdrs/types/map/struct.Map.html) -> HashMap<String, T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L350) |
  -| udt | Rust struct + custom [implementation into value](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L467) |
  +| list | List -> Vec<T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L159) |
  +| set | List -> Vec<T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L159)|
  +| map | Map -> HashMap<String, T> [example](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L185) |
  +| udt | Rust struct + custom [implementation into value](https://github.com/AlexPikalov/cdrs/blob/master/examples/all.rs#L211) |
  