Update to Laravel 8

Co-authored-by: Matthew Penner <me@matthewp.io>

.github/workflows/tests.yml

@@ -19,9 +19,9 @@ jobs:
           - 3306
         options: --health-cmd="mysqladmin ping" --health-interval=10s --health-timeout=5s --health-retries=3
     strategy:
-      fail-fast: true
+      fail-fast: false
       matrix:
-        php: [7.3, 7.4]
+        php: [7.4, 8.0]
     name: PHP ${{ matrix.php }}
     steps:
       - name: checkout
@@ -44,7 +44,7 @@ jobs:
         with:
           php-version: ${{ matrix.php }}
           extensions: cli, openssl, gd, mysql, pdo, mbstring, tokenizer, bcmath, xml, curl, zip
-          tools: composer:v1
+          tools: composer:v2
           coverage: none
       - name: configure
         run: cp .env.ci .env