Add new PHP versions to travis.yml

Author: shabbyrobe

.travis.yml

@@ -18,6 +18,9 @@ matrix:
     - { dist: trusty , php: "hhvm-3.18" }
     - { dist: trusty , php: "hhvm-nightly" }
     - { dist: trusty , php: "nightly" }
+    - { dist: trusty , php: "7.4" }
+    - { dist: trusty , php: "7.3" }
+    - { dist: trusty , php: "7.2" }
     - { dist: trusty , php: "7.1" }
     - { dist: trusty , php: "7.0" }
     - { dist: trusty , php: "5.6" }