Add PHP 7.2 to Travis build configuration

Author: raissanorth

.travis.yml

@@ -14,6 +14,8 @@ matrix:
       env: DB=PGSQL PHPUNIT_TEST=1
     - php: 7.1
       env: DB=MYSQL PHPUNIT_COVERAGE_TEST=1
+    - php: 7.2
+      env: DB=MYSQL PHPUNIT_TEST=1
 
 before_script:
 # Init PHP