v1.2.0

• Fix: Fix error reporting when parsing invalid SSH server URL.
  (#15 by @clue)

• Enhanced documentation for ReactPHP's new HTTP client.
  (#21 by @SimonFrings)

• Improve test suite and add .gitattributes to exclude dev files from exports.
  Prepare PHP 8 support, update to PHPUnit 9 and simplify test matrix.
  (#14 by @clue and #16, #18, #19 and 22 by @SimonFrings)