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
These repos will not persist beyond the transaction.
        When specifying multiple repos, separate them with a C(",").
      - As of Ansible 2.7, this can alternatively be a list instead of C(",")
        separated string
    version_added: "0.9"
  disablerepo:
    description:
      - I(Repoid) of repositories to disable for the install/update operation.
        These repos will not persist beyond the transaction.
        When specifying multiple repos, separate them with a C(",").
      - As of Ansible 2.7, this can alternatively be a list instead of C(",")
        separated string
    version_added: "0.9"
  conf_file:
    description:
      - The remote yum configuration file to use for the transaction.
    version_added: "0.6"
  disable_gpg_check:
    description:
      - Whether to disable the GPG checking of signatures of packages being
        installed. Has an effect only if state is I(present) or I(latest).
    type: bool
    default: "no"
    version_added: "1.2"
  skip_broken:
    description:
      - Skip packages with broken dependencies(devsolve) and are causing problems.
    type: bool
    default: "no"
    version_added: "2.3"