Also test PHP 7.3

Author: Toflar

.travis.yml

@@ -10,9 +10,12 @@ matrix:
     - php: 7.1
       env: COMPOSER_FLAGS='--prefer-lowest --prefer-stable'
     - php: 7.2
-      env: COVERAGE='--coverage-clover build/logs/clover.xml'
     - php: 7.2
       env: COMPOSER_FLAGS='--prefer-lowest --prefer-stable'
+    - php: 7.3
+      env: COVERAGE='--coverage-clover build/logs/clover.xml'
+    - php: 7.3
+      env: COMPOSER_FLAGS='--prefer-lowest --prefer-stable'
     - php: 7.4snapshot
     - php: 7.4snapshot
       env: COMPOSER_FLAGS='--prefer-lowest --prefer-stable'