Update guzzlehttp/psr7 requirement from ^2.12 to ^3.0 (#71)

* Update guzzlehttp/psr7 requirement from ^2.12 to ^3.0

Updates the requirements on [guzzlehttp/psr7](https://github.com/guzzle/psr7) to permit the latest version.
- [Release notes](https://github.com/guzzle/psr7/releases)
- [Changelog](https://github.com/guzzle/psr7/blob/3.0/CHANGELOG.md)
- [Commits](guzzle/psr7@2.12.0...3.0.0)

---
updated-dependencies:
- dependency-name: guzzlehttp/psr7
  dependency-version: 3.0.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

* Update guzzlehttp/psr7 version constraints

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Jesse Donat <donatj@gmail.com>

Update php-mock/php-mock-phpunit requirement from ^2.13 to ^2.14 (#57)

Updates the requirements on [php-mock/php-mock-phpunit](https://github.com/php-mock/php-mock-phpunit) to permit the latest version.
- [Release notes](https://github.com/php-mock/php-mock-phpunit/releases)
- [Commits](php-mock/php-mock-phpunit@2.13.0...2.14.0)

---
updated-dependencies:
- dependency-name: php-mock/php-mock-phpunit
  dependency-version: 2.14.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Update README

Merge pull request #18 from CorpusPHP/fix/ReplaceDefaultHeaders

ResponseSender - Replace default headers

Merge pull request #5 from CorpusPHP/feature/AuthorizationHeaderPartP…

…arser

Adds Authorization Header Parser "AuthorizationPartParser"

Update docs

Small doc improvements

Merge pull request #1 from CorpusPHP/test/Php72

Lower PHP Requirement to 7.2

Fix up configuration