Use more recent PyPy3 on Travis CI

jstasiak · jstasiak · commit d0e4712eaa69 · 2017-06-13T08:34:17.000+02:00
The default PyPy3 is really old (implements Python 3.2) and some
packages won't cooperate with it anymore.
diff --git a/.travis.yml b/.travis.yml
@@ -6,7 +6,7 @@ python:
     - "3.5"
     - "3.6"
     - "pypy"
-    - "pypy3"
+    - "pypy3.3-5.2-alpha1"
 matrix:
     fast_finish: true
 install:
