Allow pypy/pypy3 to fail for now

Author: felixonmars

.travis.yml

@@ -7,5 +7,9 @@ python:
   - "3.5"
   - "pypy"
   - "pypy3"
+matrix:
+  allow_failures:
+    - python: "pypy"
+    - python: "pypy3"
 install: pip install -U pytest pytest-runner
 script: python setup.py ptr