Only test supported releases and PHP versions

.travis.yml

@@ -5,15 +5,12 @@ sudo: false
 language: php
 
 php:
-  - 5.3
-  - 5.4
-  - 5.5
   - 5.6
   - 7.0
 
 env:
   global:
-    - DB=MYSQL CORE_RELEASE=3.2
+    - DB=MYSQL CORE_RELEASE=3
     - MODULE_PATH=iframe
     - COVERAGE=0
 
@@ -22,14 +19,10 @@ matrix:
     - php: 5.6
       env: DB=MYSQL CORE_RELEASE=3
     - php: 5.6
-      env: DB=MYSQL CORE_RELEASE=3.1
-    - php: 5.6
-      env: DB=PGSQL CORE_RELEASE=3.2
-    - php: 5.6
-      env: DB=MYSQL CORE_RELEASE=3.3
+      env: DB=PGSQL CORE_RELEASE=3
     # Allowed to fail, meaning delayed code coverage reports
     - php: 5.5.9
-      env: DB=MYSQL CORE_RELEASE=3.2 COVERAGE=1
+      env: DB=MYSQL CORE_RELEASE=3 COVERAGE=1
   allow_failures:
     - php: 7.0
     - php: 5.5.9