Use never verson of pypy on travis.

.travis.yml

@@ -3,6 +3,22 @@ cache:
   directories:
     - $HOME/.cache/pip
 
+# Pending https://github.com/travis-ci/travis-ci/issues/5027
+before_install:
+  - |
+      if [ "$TRAVIS_PYTHON_VERSION" = "pypy" ]; then
+        export PYENV_ROOT="$HOME/.pyenv"
+        if [ -f "$PYENV_ROOT/bin/pyenv" ]; then
+          cd "$PYENV_ROOT" && git pull
+        else
+          rm -rf "$PYENV_ROOT" && git clone --depth 1 https://github.com/yyuu/pyenv.git "$PYENV_ROOT"
+        fi
+        export PYPY_VERSION="4.0.1"
+        "$PYENV_ROOT/bin/pyenv" install "pypy-$PYPY_VERSION"
+        virtualenv --python="$PYENV_ROOT/versions/pypy-$PYPY_VERSION/bin/python" "$HOME/virtualenvs/pypy-$PYPY_VERSION"
+        source "$HOME/virtualenvs/pypy-$PYPY_VERSION/bin/activate"
+      fi
+
 language: python
 
 matrix: