.travis.yml: Make pypy not an allow_failures

Since it seems to work now :-)

.travis.yml

@@ -8,10 +8,7 @@ env:
     - TOXENV=py32
     - TOXENV=py33
     - TOXENV=py34
-matrix:
-  allow_failures:
-    - env: TOXENV=pypy
-  fast_finish: true
+    - TOXENV=pypy
 install:
     - travis_retry pip install tox==1.6.1
 script: