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 hasattr(po, 'ui_envra'):
            return po.ui_envra
        return '%s:%s-%s-%s.%s' % (po.epoch, po.name, po.version, po.release, po.arch)
    def is_group_env_installed(self, name):
        name_lower = name.lower()
        if yum.__version_info__ >= (3, 4):
            groups_list = self.yum_base.doGroupLists(return_evgrps=True)
        else:
            groups_list = self.yum_base.doGroupLists()
        
        groups = groups_list[0]
        for group in groups:
            if name_lower.endswith(group.name.lower()) or name_lower.endswith(group.groupid.lower()):
                return True
        if yum.__version_info__ >= (3, 4):
            
            envs = groups_list[2]
            for env in envs:
                if name_lower.endswith(env.name.lower()) or name_lower.endswith(env.environmentid.lower()):
                    return True
        return False
    def is_installed(self, repoq, pkgspec, qf=None, is_pkg=False):