chore(travis): use -f flag in coveralls submission script

Gustavo Henke · Gustavo Henke · commit e94aa198b9a0 · 2014-06-22T00:40:33.000-03:00
As it's always failing (for no reason), we'll simply force execution
to see if anything changes!
diff --git a/.travis.yml b/.travis.yml
@@ -4,7 +4,7 @@ node_js:
 
 # Submit coverage data to coveralls
 after_success:
-  - grunt coveralls:core
+  - grunt -f coveralls:core
 
 env:
   global:
