add method parameter validations in github-apis

[itaditya]

The functions don't check if the passed parameter even exist or not. This can cause issues while usage.

[JasonEtco]

The Octokit methods (and the Octokit library) all have validation to make sure that the required parameters are passed. This was introduced in a fairly recent version, not sure which, so you might want to upgrade and see if that helps.

[itaditya]

Oh thanks for pointing this out !!