Update .travis.yml to match framework

.travis.yml

@@ -27,8 +27,13 @@ env:
 
 matrix:
   allow_failures:
-    - php: hhvm-nightly
+    - php: hhvm
+    - php: 7.0
+    - php: nightly
+
   include:
+    - php: 5.4
+      env: DB=MYSQL PDO=1
     - php: 5.5
       env: DB=MYSQL
     - php: 5.6
@@ -37,7 +42,11 @@ matrix:
       env: DB=MYSQL BEHAT_TEST=1
     - php: 5.3
       env: DB=MYSQL
-    - php: hhvm-nightly
+    - php: 7.0
+      env: DB=MYSQL
+    - php: nightly
+      env: DB=MYSQL
+    - php: hhvm
       env: DB=MYSQL
 
 before_script: