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
"""
        checks the package list to see if any packages are
        involved in an incomplete transaction
        """
        conflicts = []
        if not transaction_helpers:
            return conflicts
        
        
        pkglist_nvreas = (splitFilename(pkg) for pkg in pkglist)
        
        
        unfinished_transactions = find_unfinished_transactions()
        for trans in unfinished_transactions:
            steps = find_ts_remaining(trans)
            for step in steps:
                
                
                (action, step_spec) = step
                (n, v, r, e, a) = splitFilename(step_spec)
                
                
                for pkg in pkglist_nvreas:
                    
                    
                    
                    label = "%s-%s" % (n, a)
                    if n == pkg[0] and a == pkg[4]:
                        if label not in conflicts:
                            conflicts.append("%s-%s" % (n, a))