I am using the yum module to lock the release version for a RHEL 7.6 machine to 7.7 version. However the yum --releasever option does not set the release version to 7.7. I am using Ansible 2.7.10 version.
Here is the discussion regarding the issue: 
https://access.redhat.com/discussions/4774501

ISSUE TYPE
Bug Report

COMPONENT NAME
yum --releasever

ANSIBLE VERSION
2.7.10 

STEPS TO REPRODUCE
name: installing updated packages
yum:
name: '*'
state: latest
releasever: '7.7'

ACTUAL RESULTS
Play runs successfully however it does not update the release version of the server
if not repoq:
            pkgs = []
            try:
                e, m, _ = self.yum_base.pkgSack.matchPackageNames([pkgspec])
                pkgs = e + m
                if not pkgs:
                    pkgs.extend(self.yum_base.returnPackagesByDep(pkgspec))
            except Exception as e:
                self.module.fail_json(msg="Failure talking to yum: %s" % to_native(e))
            return [self.po_to_envra(p) for p in pkgs]
        else:
            myrepoq = list(repoq)
            r_cmd = ['--disablerepo', ','.join(self.disablerepo)]
            myrepoq.extend(r_cmd)
            r_cmd = ['--enablerepo', ','.join(self.enablerepo)]
            myrepoq.extend(r_cmd)
            cmd = myrepoq + ["--qf", qf, pkgspec]
            rc, out, err = self.module.run_command(cmd)
            if rc == 0:
                return [p for p in out.split('\n') if p.strip()]
            else:
                self.module.fail_json(msg='Error from repoquery: %s: %s' % (cmd, err))
        return []
    def is_update(self, repoq, pkgspec, qf=def_qf):