Merge pull request #1661 from andreybolonin/patch-1

add php 7.4snapshot

.travis.yml

@@ -1,6 +1,6 @@
 language: php
 
-dist: precise
+dist: xenial
 
 php:
     - 5.3
@@ -11,19 +11,29 @@ php:
     - 7.1
     - 7.2
     - 7.3
+    - 7.4snapshot
 
 matrix:
     include:
+        - php: 5.3
+          dist: precise
+          env: COMPOSER_MEMORY_LIMIT=3G
+        - php: 5.4
+          dist: trusty
+        - php: 5.5
+          dist: trusty
         - php: 7.0
           env: COVERAGE=1
-        - php: 5.3
-          env: COMPOSER_MEMORY_LIMIT=3G
         - php: 7.3
           env: DEPENDENCIES="--ignore-platform-reqs"
     exclude:
         - php: 5.3
+        - php: 5.4
+        - php: 5.5
         - php: 7.0
         - php: 7.3
+    allow_failures:
+        - php: 7.4snapshot
 
 cache:
     directories: