Disable fast finish as it is buggy w.r.t. notifications...

Disable fast finish as it is buggy w.r.t. notifications https://github.com/travis-ci/travis-ci/issues/4928

 [ci skip]
Signed-off-by: Edward Z. Yang <ezyang@cs.stanford.edu>

.travis.yml

@@ -36,7 +36,6 @@ script:
 matrix:
   allow_failures:
    - env: GHCVER=head
-  fast_finish: true
 
 notifications:
   irc: