Centos8 ansible execution fix (#423)

* install python2 pyyaml for ansible

* need requests for uf image ansible

* combine pip steps

Author: jmeixensperger

py23-image/centos-8/Dockerfile

@@ -26,4 +26,5 @@ RUN wget https://www.python.org/ftp/python/3.7.4/Python-3.7.4.tgz \
 RUN yum remove -y --setopt=tsflags=noscripts gcc openssl-devel bzip2-devel libffi-devel \
     && yum autoremove -y \
     && yum clean all
-RUN pip3 --no-cache-dir install ansible requests
+RUN pip3 --no-cache-dir install ansible requests \
+    && pip --no-cache-dir install pyyaml requests