fix .travis.yml allowed failure matrix

Author: oohnoitz

.travis.yml

@@ -18,8 +18,8 @@ env:
 matrix:
   fast_finish: true
   allow_failures:
-    - env: DRIVER=mysqli SEARCH_BUILD=SPHINX3
-    - env: DRIVER=pdo SEARCH_BUILD=SPHINX3
+    - env: DRIVER=mysqli SEARCH_BUILD=SPHINX3 EXCLUDE_GROUP="--exclude-group=Manticore"
+    - env: DRIVER=pdo SEARCH_BUILD=SPHINX3 EXCLUDE_GROUP="--exclude-group=Manticore"
 
 before_install:
   - mkdir $HOME/search