contrib/docker/fedora20

help: clarify quotes are needed for filesets.size expressions

FROM fedora:20
RUN yum install -y gcc
RUN yum install -y python-devel python-docutils
RUN yum install -y make
RUN yum install -y rpm-build
RUN yum install -y gettext
# For creating repo meta data
RUN yum install -y createrepo