Update README.md (#174)

Author: Greg Bowler

README.md

@@ -10,19 +10,19 @@ This repository is an implementation of the PSR-7 interfaces for use within PHP.
 ***
 
 <a href="https://github.com/PhpGt/Http/actions" target="_blank">
-	<img src="https://badge.status.php.gt/http-build" alt="PHP.Gt/Http build status" />
+	<img src="https://badge.status.php.gt/http-build.svg" alt="PHP.Gt/Http build status" />
 </a>
 <a href="https://scrutinizer-ci.com/g/PhpGt/Http" target="_blank">
-	<img src="https://badge.status.php.gt/http-quality" alt="PHP.Gt/Http code quality" />
+	<img src="https://badge.status.php.gt/http-quality.svg" alt="PHP.Gt/Http code quality" />
 </a>
 <a href="https://scrutinizer-ci.com/g/PhpGt/Http" target="_blank">
-	<img src="https://badge.status.php.gt/http-coverage" alt="PHP.Gt/Http code coverage" />
+	<img src="https://badge.status.php.gt/http-coverage.svg" alt="PHP.Gt/Http code coverage" />
 </a>
 <a href="https://packagist.PhpGt/packages/PhpGt/Http" target="_blank">
-	<img src="https://badge.status.php.gt/http-version" alt="PHP.Gt/Http latest release" />
+	<img src="https://badge.status.php.gt/http-version.svg" alt="PHP.Gt/Http latest release" />
 </a>
 <a href="http://www.php.gt/Http" target="_blank">
-	<img src="https://badge.status.php.gt/http-docs" alt="PHP.Gt/Http documentation" />
+	<img src="https://badge.status.php.gt/http-docs.svg" alt="PHP.Gt/Http documentation" />
 </a>
 
-[fig]: https://www.php-fig.org/psr/psr-7/
+[fig]: https://www.php-fig.org/psr/psr-7/