Don't run tests with Python 2.6.

letsencrypt-auto-source/Dockerfile.centos6

@@ -5,13 +5,7 @@ FROM centos:6
 
 RUN yum install -y epel-release
 
-# Install pip and sudo:
-RUN yum install -y python-pip sudo
-# Use pipstrap to update to a stable and tested version of pip
-COPY ./pieces/pipstrap.py /opt
-RUN /opt/pipstrap.py
-# Pin pytest version for increased stability
-RUN pip install pytest==3.2.5
+RUN yum install -y sudo
 
 # Add an unprivileged user:
 RUN useradd --create-home --home-dir /home/lea --shell /bin/bash --groups wheel --uid 1000 lea

letsencrypt-auto-source/tests/centos6_tests.sh

@@ -77,5 +77,10 @@ if [ "$($VENV_PATH/bin/python -V 2>&1 | cut -d" " -f2 | cut -d. -f1)" != 3 ]; th
 fi
 unset VENV_PATH
 
-# test using python3
+# test using python2.7
+source /opt/rh/python27/enable
+# Use pipstrap to update to a stable and tested version of pip
+certbot/letsencryot-auto-source/pieces/pipstrap.py
+# Pin pytest version for increased stability
+pip install pytest==3.2.5
 pytest -v -s certbot/letsencrypt-auto-source/tests