feat(service): Add Instagram service

[alankan886]

Add support for Instagram service.

I would be happy to add unit tests, but I skimmed through #1 and it seems like the decision on testing is still pending.

[nikoksr]

Hey @alankan886, thanks for your contribution and thanks for alerting me to the fact that ahmdrz/goinsta currently seems pretty inactive. I will try to contact the developer. If I can't reach him, I really only see three solutions:

1. We fork the repo and maintain it ourselves (can't do it myself atm too short on time)
2. We don't support Instagram for the time being
3. We use the inactive library, but clearly advise in the documentation not to use the Instagram service

I would like to know your opinion on this @j-wil @KrishanBhalla.

Until we make a decision, I'm leaving the PR open. Really, I appreciate your contribution and would love to merge it right now but we need to decide this first; sorry!

[alankan886]

@nikoksr, thanks for letting me know, that's unfortunate.

I think with option 1, we will still be relying on ahmdrz/goinsta's private API (official Instagram API doesn't seem to allow DMs), so I don't think it's beneficial to go with option 1. I feel like it comes down to how long the private API's DM feature will last, it works fine atm, but I would definitely ask the developers if they expect the API to work with Instagram's future updates.

[nikoksr]

@alankan886 I have already contacted the developer and am now waiting for his response.

Just gave this a quick Google search and found this.

[alankan886]

@nikoksr ah good find, so perhaps just wait until Facebook publishes the updated API.

[nikoksr]

@alankan886 yes, then possibly our best choice. We are now waiting for the answer from the developer and then decide. Again, I'm really sorry for the inconvenience. I was very busy the days, otherwise I would have answered earlier that we must first contact the developer.

[j-wil]

@nikoksr I think you're on the right track here we have to imagine notify running in production environments where people may rely on the notifications produced by our work here.

+1 waiting for messenger insta integration

[nikoksr]

Closing this for now. Will update the Facebook-Messenger issue (#4).