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
#
    
    
    
    
    
    
    yumdnf_argument_spec['argument_spec']['use_backend'] = dict(default='auto', choices=['auto', 'yum', 'yum4', 'dnf'])
    module = AnsibleModule(
        **yumdnf_argument_spec
    )
    module_implementation = YumModule(module)
    module_implementation.run()
if __name__ == '__main__':
    main()