Update guzzlehttp/guzzle requirement from ~6.0 to ~6.0 || ~7.0 (#7)

Updates the requirements on [guzzlehttp/guzzle](https://github.com/guzzle/guzzle) to permit the latest version.
- [Release notes](https://github.com/guzzle/guzzle/releases)
- [Changelog](https://github.com/guzzle/guzzle/blob/master/CHANGELOG.md)
- [Commits](guzzle/guzzle@6.0.0...7.0.1)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

composer.json

@@ -22,7 +22,7 @@
     "require": {
         "php": ">=7.2",
         "illuminate/support": "^7.0",
-        "guzzlehttp/guzzle": "~6.0"
+        "guzzlehttp/guzzle": "~6.0 || ~7.0"
     },
     "autoload": {
         "psr-4": {