Fix venv module installation on oraclelinux

Signed-off-by: Benoit Donneaux <benoit@leastauthority.com>

Author: btlogy

.circleci/Dockerfile.oraclelinux

@@ -8,16 +8,16 @@ ENV VIRTUALENV_PATH /tmp/venv
 ENV BUILD_SRC_ROOT /tmp/project
 
 # XXX net-tools is actually a Tahoe-LAFS runtime dependency!
-RUN yum install --assumeyes \
+RUN /bin/bash -c 'yum install --assumeyes \
     git \
     sudo \
     make automake gcc gcc-c++ \
     python${PYTHON_VERSION} \
     libffi-devel \
     openssl-devel \
     libyaml \
-    /usr/bin/virtualenv \
-    net-tools
+    python${PYTHON_VERSION%%.*}-virtualenv \
+    net-tools'
 
 # 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.