change php version

Dan Richelson · Dan Richelson · commit 09efa548a7d5 · 2016-12-23T15:30:40.000-08:00
diff --git a/circle.yml b/circle.yml
@@ -1,6 +1,6 @@
 machine:
   php:
-    version: 5.5.21
+    version: 5.6.17
 
 test:
   override:
