Add owners files for the C++ code

[roberthbailey]

Two reasons:

1. To document that @devjgm is handling the bulk of the code reviews (especially for style).
2. This will cause the blunderbuss plugin for prow to auto assign code reviews.

/assign @devjgm

[google-oss-robot]

@roberthbailey: GitHub didn't allow me to assign the following users: devjgm.

Note that only googleforgames members, repo collaborators and people who have commented on this issue/PR can be assigned. Additionally, issues/PRs can only have 10 assignees at the same time.
For more information please see the contributor guide

In response to this:

Two reasons:

1. To document that @devjgm is handling the bulk of the code reviews (especially for style).
2. This will cause the blunderbuss plugin for prow to auto assign code reviews.

/assign @devjgm

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[google-oss-robot]

The following users are mentioned in OWNERS file(s) but are not members of the googleforgames org.

Once all users have been added as members of the org, you can trigger verification by writing /verify-owners in a comment.

• devjgm
  • examples/cpp-simple/OWNERS
  • sdks/cpp/OWNERS

[agones-bot]

Build Succeeded 👏

Build Id: e7819faa-22ae-451c-9a9d-ffae0ad72531

The following development artifacts have been built, and will exist for the next 30 days:

• image: gcr.io/agones-images/agones-controller:1.1.0-264dfa9
• image: gcr.io/agones-images/agones-sdk:1.1.0-264dfa9
• image: gcr.io/agones-images/agones-ping:1.1.0-264dfa9
• Linux C++ SDK (build): agonessdk-1.1.0-264dfa9-linux-arch_64.tar.gz
• SDK Server: agonessdk-server-1.1.0-264dfa9.zip

A preview of the website (the last 30 builds are retained):

• https://264dfa9-dot-preview-dot-agones-images.appspot.com/

To install this version:

• git fetch https://github.com/GoogleCloudPlatform/agones.git pull/1118/head:pr_1118 && git checkout pr_1118
• helm install install/helm/agones --namespace agones-system --name agones --set agones.image.tag=1.1.0-264dfa9

[google-oss-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: pooneh-m, roberthbailey

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [pooneh-m,roberthbailey]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment