Run tests on PHP 7.4 and simplify test matrix

.travis.yml

@@ -1,25 +1,28 @@
 language: php
 
-php:
-# - 5.3 # requires old distro, see below
-  - 5.4
-  - 5.5
-  - 5.6
-  - 7
-  - hhvm # ignore errors, see below
-
 # lock distro so new future defaults will not break the build
 dist: trusty
 
 matrix:
   include:
     - php: 5.3
       dist: precise
+      script:
+        - vendor/bin/phpunit --coverage-text --verbose || [[ $? = 139 ]] # ignore SEGFAULT on legacy PHP 5.3 only
+    - php: 5.4
+    - php: 5.5
+    - php: 5.6
+    - php: 7.0
+    - php: 7.1
+    - php: 7.2
+    - php: 7.3
+    - php: 7.4
+    - php: hhvm-3.18
   allow_failures:
-    - php: hhvm
+    - php: hhvm-3.18
 
 install:
   - composer install --no-interaction
 
 script:
-  - vendor/bin/phpunit --coverage-text --verbose || ([[ $? = 139 ]] && echo && echo "Ignoring SEGFAULT.." >&2)
+  - vendor/bin/phpunit --coverage-text