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
- name: install a list of packages (suitable replacement for 2.11 loop deprecation warning)
  yum:
    name:
      - nginx
      - postgresql
      - postgresql-server
    state: present
- name: install a list of packages with a list variable
  yum:
    name: "{{ packages }}"
  vars:
    packages:
    - httpd
    - httpd-tools
- name: remove the Apache package
  yum:
    name: httpd
    state: absent
- name: install the latest version of Apache from the testing repo
  yum:
    name: httpd
    enablerepo: testing
    state: present
- name: install one specific version of Apache
  yum:
    name: httpd-2.2.29-1.4.amzn1
    state: present
- name: upgrade all packages
  yum:
    name: '*'