Travis: allow failures on PyPy

Until travis-ci/travis-ci#5027 is resolved the
builds on PyPy are going to fail because the Apache.org servers use
HTTPS with SNI.

Author: acdha

.travis.yml

@@ -17,6 +17,10 @@ env:
     - SOLRCLOUD=false
     - SOLRCLOUD=true
 
+matrix:
+    allow_failures:
+        - python: 'pypy'
+
 addons:
   apt_packages:
     - default-jdk