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:
    description:
      - A package name or package specifier with version, like C(name-1.0).
      - If a previous version is specified, the task also needs to turn C(allow_downgrade) on.
        See the C(allow_downgrade) documentation for caveats with downgrading packages.
      - When using state=latest, this can be C('*') which means run C(yum -y update).
      - You can also pass a url or a local path to a rpm file (using state=present).
        To operate on several packages this can accept a comma separated string of packages or (as of 2.0) a list of packages.
    aliases: [ pkg ]
  exclude:
    description:
      - Package name(s) to exclude when state=present, or latest
    version_added: "2.0"
  list:
    description:
      - "Package name to run the equivalent of yum list --show-duplicates <package> against. In addition to listing packages,
        use can also list the following: C(installed), C(updates), C(available) and C(repos)."
      - This parameter is mutually exclusive with C(name).
  state:
    description:
      - Whether to install (C(present) or C(installed), C(latest)), or remove (C(absent) or C(removed)) a package.
      - C(present) and C(installed) will simply ensure that a desired package is installed.
      - C(latest) will update the specified package if it's not of the latest available version.
      - C(absent) and C(removed) will remove the specified package.
      - Default is C(None), however in effect the default action is C(present) unless the C(autoremove) option is
        enabled for this module, then C(absent) is inferred.
    choices: [ absent, installed, latest, present, removed ]
  enablerepo:
    description:
      - I(Repoid) of repositories to enable for the install/update operation.