Update get_meetup_events() for Meetup v3 api, replace ids with urls

[bcsnipes]

This replaces the use of group_ids (v2) with group_urls (v3).

With v2, we could perform a single GET request tagged with multiple group_ids.

But with v3, we need to loop through each group_url and perform multiple GET requests. We then need to loop through the results to extract multiple events from each group.

It's working for me, but please have a check and let me know if it's working in your environment or what other changes I could make.

[allella]

Nice. I'll experiment with it perhaps on Sunday as I want to figure the right way to test this and do the merge. I think I can setup a remote branch pointing at your v3 code and quickly checkout that code and see how it does.

[allella]

@bcsnipes Thanks. I checked out a copy of your branch on the production server and ran the app.py.

For your reference, this is how I did it.

git remote add bcsnipes https://github.com/bcsnipes/upstate_tech_cal_service.git
git fetch bcsnipes
git branch -a
git checkout v3

This allowed me to test your v3 branch on the production site.

I'm going to merge this pull request and then it will merge your code into the master branch here and then I'll check out master on the production site and it will have your pull request in it.