Merge pull request #631 from Gizra/feature/drupal9

[PP] 630 Begin support for Drupal 9

Author: pfrenssen

.travis.yml

@@ -14,17 +14,21 @@ env:
     - TEST_SUITE=8.7.x
     - TEST_SUITE=8.8.x
     - TEST_SUITE=8.9.x
+    - TEST_SUITE=9.0.x
     - TEST_SUITE=PHP_CodeSniffer
 
 # Only run the coding standards check once.
 matrix:
   exclude:
+    - php: 7.2
+      env: TEST_SUITE=9.0.x
     - php: 7.2
       env: TEST_SUITE=PHP_CodeSniffer
     - php: 7.4
       env: TEST_SUITE=PHP_CodeSniffer
   allow_failures:
     - php: 7.4
+    - env: TEST_SUITE=9.0.x
 
 mysql:
   database: og