.travis.yml in rmagick-2.15.3 vs .travis.yml in rmagick-2.15.4

@@ -1,14 +1,15 @@
 language: ruby
 
 os:
   - linux
 
+sudo: required
+
 env:
   # Currently successful release
   - IMAGEMAGICK_VERSION=6.6.9-10
-  - IMAGEMAGICK_VERSION=6.6.9-10 STYLE_CHECKS=true
   # Ubuntu's current stable release
   - IMAGEMAGICK_VERSION=6.7.7-10
   # Latest 6.7 release
   - IMAGEMAGICK_VERSION=6.7.9-10
   # Latest 6.8 release
@@ -29,12 +30,10 @@
   - 2.2
 
 matrix:
   exclude:
     - rvm: 1.8
-      env: IMAGEMAGICK_VERSION=6.6.9-10 STYLE_CHECKS=true
-    - rvm: 1.8
       env: IMAGEMAGICK_VERSION=6.7.9-10
     - rvm: 1.8
       env: IMAGEMAGICK_VERSION=6.7.7-10
     - rvm: 1.8
       env: IMAGEMAGICK_VERSION=6.8.9-10 CONFIGURE_OPTIONS=--enable-hdri
@@ -51,15 +50,19 @@
     - rvm: 2.0
       env: IMAGEMAGICK_VERSION=6.8.9-10
     - rvm: 2.0
       env: IMAGEMAGICK_VERSION=6.8.9-10 CONFIGURE_OPTIONS=--enable-hdri
   allow_failures:
-    - rvm: 1.8
-    - rvm: 2.2
-    - env: IMAGEMAGICK_VERSION=6.6.9-10 STYLE_CHECKS=true
     - env: IMAGEMAGICK_VERSION=6.7.7-10
     - env: IMAGEMAGICK_VERSION=6.7.9-10
+      rvm: 2.1
+    - env: IMAGEMAGICK_VERSION=6.7.9-10
+      rvm: 2.2
+    - env: IMAGEMAGICK_VERSION=6.8.9-10
+      rvm: 2.1
     - env: IMAGEMAGICK_VERSION=6.8.9-10 CONFIGURE_OPTIONS=--enable-hdri
+      rvm: 2.1
+    - env: IMAGEMAGICK_VERSION=latest
 
 notifications:
   webhooks:
     urls:
       - https://webhooks.gitter.im/e/a98c1112f5d60f97a532