PHP 8 support

Author: andrew-nuwber

.gitignore

@@ -5,4 +5,5 @@
 test/output/
 .idea
 /composer.phar
+composer.lock
 test.php

.travis.yml

@@ -1,18 +1,17 @@
 language: php
 php:
-  - '5.6'
-  - '7.0'
   - '7.1'
   - '7.2'
   - '7.3'
   - '7.4'
+  - '8.0
 install:
   - composer install --no-interaction
 script:
   - mkdir -p test/output/report
   - composer test
 after_script:
-  - php vendor/bin/coveralls
+  - php vendor/bin/php-coveralls
 notifications:
   slack:
     secure: mw6HF2KR0YwYcIaYvV6qjuWC+XSIP8SQOe13VwmGf3b783hMcZDZTUS9N4bIfpwYi74A9qmzKdc425OSu45nceAf7hzFusCY5rYMoLQK/ksJ7sd+ay7tWhPRuomG1w8idTyXtzce23zOfBtOCHQakbavH2Uz6mh5lJYPFlMKW4c=

composer.json

@@ -9,24 +9,23 @@
   ],
   "minimum-stability": "stable",
   "scripts": {
-    "test": "./vendor/bin/phpunit",
-    "fix-style": "php-cs-fixer fix ."
+    "test": "./vendor/bin/phpunit"
   },
   "require": {
-    "php": "^5.6 || ^7.0",
+    "php": "^7.1 || ^8.0",
     "php-http/httplug": "^1.0 || ^2.0",
     "php-http/message": "^1.0",
     "php-http/client-implementation": "^1.0",
     "php-http/discovery": "^1.0"
   },
   "require-dev": {
-    "phpunit/phpunit": "^4.8 || ^5.4",
+    "phpunit/phpunit": "^9.0",
     "php-http/guzzle6-adapter": "^1.0",
-    "mockery/mockery": "^0.9.4",
-    "friendsofphp/php-cs-fixer": "^1.11",
+    "mockery/mockery": "^1.4",
     "nyholm/nsa": "^1.0",
-    "satooshi/php-coveralls": "dev-master",
-    "phpunit/phpcov": "2.*"
+    "php-coveralls/php-coveralls": "^2.4",
+    "phpunit/phpcov": "^8.0",
+    "friendsofphp/php-cs-fixer": "^2.18"
   },
   "autoload": {
     "psr-4": {