Allow PHP 8.x use.

Author: chrisryan

.github/workflows/php.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-18.04
     strategy:
       matrix:
-        php-versions: ['7.0', '7.1', '7.2', '7.3', '7.4']
+        php-versions: ['7.0', '7.1', '7.2', '7.3', '7.4', '8.0', '8.1']
     steps:
     - name: Checkout
       uses: actions/checkout@v2

.travis.yml

@@ -4,6 +4,9 @@ php:
   - 7.1
   - 7.2
   - 7.3
+  - 7.4
+  - 8.0
+  - 8.1
   - nightly
 env:
   - PREFER_LOWEST="--prefer-lowest --prefer-stable"

composer.json

@@ -3,12 +3,12 @@
     "description": "Collection of classes to assist with units of time.",
     "license": "MIT",
     "require": {
-        "php": "^7.0"
+        "php": "^7.0 || ^8.0"
     },
     "require-dev": {
-        "chadicus/coding-standard": "^1.7",
+        "chadicus/coding-standard": "^1.7 || ^2.0",
         "php-coveralls/php-coveralls": "^2.1",
-        "phpunit/phpunit": "^6.5"
+        "phpunit/phpunit": "^6.5 || ^7.0 || ^8.0 || ^9.0"
     },
     "config" : {
         "sort-packages": true