Update build workflow

.github/workflows/build.yml

@@ -6,7 +6,13 @@ jobs:
     strategy:
       matrix:
         php:
+          - '8.0'
+          - '7.4'
+          - '7.3'
+          - '7.2'
+          - '7.1'
           - '7.0'
+          - '5.6'
     name: PHP ${{ matrix.php }} build
     env:
       PHP_CS_FIXER_IGNORE_ENV: 1
@@ -24,6 +30,10 @@ jobs:
           coverage: none
           ini-values: phar.readonly=0
 
+      - name: Wait for packagist
+        run: |
+          tests/waitPackagist.php
+
       - name: Build
         run: |
           tests/makephar.sh