Re-export all error types from awc

[mwilliammyers]

PR Type

Other

PR Checklist

Check your PR fulfills the following:

• Tests for the changes have been added / updated. (N/A)
• Documentation comments have been added / updated. (N/A)
• A changelog entry has been made for the appropriate packages.
• Format code with the latest stable rustfmt

Overview

This makes using error handling while using the awc::Client much easier.

Closes #1474

Or I can update this PR to do one of the following (in order of ascending levels of change):

1. Import the rest of the missing errors (and the rest of the API as well?) like FrozenClientRequest individually.

2. Change the error imports to:

   pub use awc::error::*;

3. Change the whole client module to:

   1. Re-export everything while keeping the current structure:

      pub use awc::error::*;
      pub use awc::*;

   2. Re-export everything to keep the same structure as awc (breaking change):

      pub use awc::*;

[codecov-commenter]

Codecov Report

Merging #1621 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1621   +/-   ##
=======================================
  Coverage   53.20%   53.20%           
=======================================
  Files         125      125           
  Lines       11762    11762           
=======================================
  Hits         6258     6258           
  Misses       5504     5504           

Impacted Files	Coverage Δ
src/lib.rs	68.42% <ø> (ø)

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[JohnTitor]

I have no objections for this. Could you also update the changelog?

[mwilliammyers]

Should I not add any other imports (or do any of the other options listed above)?

[robjtede]

I would be in favour of re exporting all the error types as you mentioned in 2.

[JohnTitor]

We'd be happy to include this in the next beta release if you could update in a few days :)

[mwilliammyers]

Done!

I also noticed the change log has a bad link:

[#1618]: https://github.com/actix/actix-web/pull/1610

I can fix that as well, unless you wanted to keep that separate?

[robjtede]

I can fix that as well, unless you wanted to keep that separate?

might as well since you spotted it 👍