Build a Docker image we can use for PyPy CI

.circleci/Dockerfile.pypy

@@ -0,0 +1,23 @@
+FROM pypy:2.7-7.1.1-jessie
+
+ENV WHEELHOUSE_PATH /tmp/wheelhouse
+ENV VIRTUALENV_PATH /tmp/venv
+# This will get updated by the CircleCI checkout step.
+ENV BUILD_SRC_ROOT /tmp/project
+
+RUN apt-get --quiet update && \
+    apt-get --quiet --yes install \
+        git \
+        lsb-release \
+        sudo \
+        build-essential \
+        libffi-dev \
+        libssl-dev \
+        libyaml-dev \
+        virtualenv
+
+# Get the project source.  This is better than it seems.  CircleCI will
+# *update* this checkout on each job run, saving us more time per-job.
+COPY . ${BUILD_SRC_ROOT}
+
+RUN "${BUILD_SRC_ROOT}"/.circleci/prepare-image.sh "${WHEELHOUSE_PATH}" "${VIRTUALENV_PATH}" "${BUILD_SRC_ROOT}"

.circleci/config.yml

@@ -406,3 +406,11 @@ jobs:
     environment:
       DISTRO: "slackware"
       TAG: "14.2"
+
+
+  build-image-pypy-2.7-7.1.1-jessie:
+    <<: *BUILD_IMAGE
+
+    environment:
+      DISTRO: "pypy"
+      TAG: "2.7-7.1.1-jessie"