context: move _manifest from committablectx to workingctx
committablectx had a _manifest implementation that was only used by the derived
workingctx class. The other derived versions, like memctx and metadataonlyctx,
define their own _manifest functions.
Let's move the function down to workingctx, and let's break it into two parts,
the _manifest part that reads from self._status, and the part that actually
builds the new manifest. This separation will let us reuse the builder code in a
future patch to answer _buildstatus with varying status inputs, since workingctx
has special behavior for _buildstatus that the other ctx's don't have.
FROM centos:centos6
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
RUN yum install -y tar
# For creating repo meta data
RUN yum install -y createrepo