add issue service methods

[shreyas1599]

• Update an Issue comment
• Labels for issues in a milestone
• Get a single milestone
• Update a milestone

[robrbecker]

@shreyas1599 Thanks for putting up this PR. I'll test it out this week.

[shreyas1599]

@robrbecker thanks. I was looking to fill in the other TODO methods as well but was waiting to see if this gets merged. But now I see in the Discussions tab that you're planning to move to OpenAPI spec so should I not do it?

[robrbecker]

You can continue with this PR. The open API generator still needs work so it will be a while before that's ready.

…

On Wed, Apr 21, 2021, 12:06 AM Shreyas Thirumalai ***@***.***> wrote: @robrbecker <https://github.com/robrbecker> thanks. I was looking to fill in the other TODO methods as well but was waiting to see if this gets merged. But now I see in the Discussions tab that you're planning to move to OpenAPI spec so should I not do it? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#240 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AACM32WX27BDV3C55X6CQSDTJZTQDANCNFSM4WOL5TRA> .

[robrbecker]

@shreyas1599 I'm circling back to this PR. I guess I had never done anything with it since I thought you were going to add more to it. Should we fix this one up and get it merged?