.travis.yml: diff against real upstream master instead of what travis is telling us.

.travis.yml

@@ -11,9 +11,9 @@ before_script:
     - git clone --depth 1 git://github.com/chneukirchen/xtools.git xtools
 
 script:
-    - echo "Checking $TRAVIS_COMMIT_RANGE"
-    - git diff --name-status "$TRAVIS_COMMIT_RANGE" > __changed_files
-    - cat __changed_files
+    - git remote add upstream git://github.com/voidlinux/void-packages.git
+    - git fetch --depth 1 upstream master
+    - git diff --name-status upstream/master > __changed_files
     - grep "^[AM].*srcpkgs/[^/]*/template$" __changed_files | awk '{print $2}' | tee __changed_templates
     - xlint `cat __changed_templates`