vec1 1.8.0

a std Vec wrapper assuring that it has at least 1 element
Documentation

# Change Log

## Version 1.8.0 (pending)

- minimal rust version is now 1.48
- updated documentation
- more tests
- deprecated the `try_` prefix usage as it created ambiguities with
  other potential `try_` versions (like try and don't panic if out of
  bounds or try and don't panic if allocation fails).
- some missing methods and trait implementations (e.g. `drain)
- fixed bug in `Vec1.splice()` which caused the code to return
  a `Size0Error` in a very specific edge case where it should
  have panicked due to a out of bounds range like `Vec.splice()`
  does.

## Version 1.7.0 (11.03.2021)

- minimal rust version is now 1.47
- support for `SmallVec1` backed by the `smallvec` crate (v>=1.6.1)
- added `no_std` support (making `std` a default feature)
- converted various `Into`/`TryInto` impls into `From`/`TryFrom` impls.
- changes in the documentation for various reasons, some functions
  have now less good documentation as they are automatically implemented
  for both `Vec1`, and `smallvec-v1::SmallVec1`.

## Version 1.6.0 (11.08.2020)

- Added the `split_off_first` and `split_off_last` methods.

## Version 1.5.1 (01.07.2020)

- Updated project to `edition="2018"` (not that this is
  a purely internal change and doesn't affect the API
  interface or minimal supported rustc version)
- Added [CONTRIBUTORS.md]./CONTRIBUTORS.md
- Updated [README.md]./README.md

## Version 1.5.0 (21.05.2020)

- minimal rust version is now 1.34
- `TryFrom` is no longer feature gated
- `vec1![]` now allows trailing `,` in all cases
- `Size0Error` now no longer has a custom
  `std::error::Error::description()` implementation.
- fixed various clippy::pedantic warnings
- updated `Cargo.toml`
- `cargo fmt`

## Version 1.4.0 (26.03.2019)

New trait impl:
- impl Default for Vec1<T> where T: Default

## Version 1.3.0 (21.03.2019)

New manual proxy methods:
- splice
- to_asci_lowercase
- to_ascii_uppercase

New Into impl for following types:
- Rc<[T]>
- Arc<[T]>
- Box<[T]>
- VecDeque<T>

### Unstable/Nightly features

New TryFrom impl for following types:
- Box<[T]>
- BinaryHeap<T>
- VecDeque<T>
- String
- &str
- &[T] where T: Clone
- &mut [T] where T: Clone

## Version 1.2.0 (20.03.2019)

- Added new `try_from_vec` which returns a `Result<Vec1<T>, Size0Error>`.
- Deprecated `from_vec` as it doesn't return a error type as error.

### Unstable/Nightly features

- New `unstable-nightly-try-from-impl` feature which adds a `TryFrom<Vec<T>>` implementation.


## Version 1.1.0

- Addead a `serde` feature implementing `Serialize`/`Deserialize`.