docker: try to follow the best practices for writing Dockerfiles
Merged multiple RUN instructions and sorted the arguments alphabetically
Reference: https://docs.docker.com/engine/userguide/eng-image/dockerfile_best-practices/
FROM centos:centos6
RUN yum install -y \
gcc \
gettext \
make \
python-devel \
python-docutils \
rpm-build \
tar
# For creating repo meta data
RUN yum install -y createrepo
# For python
RUN yum install -y \
bzip2-devel \
ncurses-devel \
openssl-devel \
readline-devel \
zlib-devel