Requesting modules to manage Github/Bitbucket/Gitlab deploy keys

Previously, issue 2626 was opened in the ansible-modules-core repository requesting a module for managing Github deploy keys, but it was never developed.

Currently, this can be accomplished using the uri module, however it requires some effort to achieve idempotency and it would be better to have native modules that can do the same thing in 1 task:

`

Since there were no takers, I decided to implement this myself. Developed a module for managing deploy keys for GitHub.

PR for github_deploy_key module: https://github.com/ansible/ansible/pull/24364

Will develop modules for Bitbucket and Gitlab as time permits.