Merge pull request #266 from Lukasa/update-pypy-builder

Use a newer PyPy builder.

Author: Lukasa

.travis.yml

@@ -4,7 +4,7 @@ python:
   - "2.7"
   - "3.4"
   - "3.5"
-  - pypy
+  - "pypy-5.3.1"
 
 env:
   - TEST_RELEASE=false HYPER_FAST_PARSE=false
@@ -19,7 +19,7 @@ matrix:
     - env: TEST_RELEASE=true HYPER_FAST_PARSE=false
   exclude:
     - env: NGHTTP2=true
-      python: pypy
+      python: "pypy-5.3.1"
 
 install:
   - ".travis/install.sh"