tests: update travis composer flags

JacobBennett · JacobBennett · commit 1d2a655802ce · 2016-07-29T23:42:57.000-04:00
diff --git a/.travis.yml b/.travis.yml
@@ -7,7 +7,6 @@ php:
 
 env:
   matrix:
-    - COMPOSER_FLAGS="--prefer-lowest"
     - COMPOSER_FLAGS=""
 
 before_script:
