Factor duplication out of Debian configuration

.circleci/config.yml

@@ -23,7 +23,7 @@ jobs:
             pip install --user tox
             ~/.local/bin/tox -e codechecks
 
-  debian-8:
+  debian-8: &DEBIAN
     docker:
       - image: "debian:8"
 
@@ -59,25 +59,4 @@ jobs:
     docker:
       - image: "debian:9"
 
-    steps:
-      - "checkout"
-
-      - run:
-          name: "Bootstrap test environment"
-          command: |
-            apt-get --quiet update
-            apt-get --quiet --yes install \
-                build-essential \
-                python2.7 \
-                python2.7-dev \
-                libffi-dev \
-                libssl-dev \
-                libyaml-dev \
-                virtualenv
-            virtualenv --python python2.7 tests
-            tests/bin/pip install tox
-
-      - run:
-          name: "Run test suite"
-          command: |
-            tests/bin/tox -e py27
+    <<: *DEBIAN