Incorporate hangout or zoom link invitation into penny chat invitation

[JnBrymn]

We are trying to guide people to have online penny chats so that Penny U is accessible to people that aren't just co-located in the same city.

Make it easy for organizers to include a hangout link. (Maybe a check box in the create?)

Similar to #131

[mrshwah]

Going to go with the Google integration on this one. It will take about the same amount of time as Zoom (need to set up OAuth for both), but will also set up some cool opportunities for other calendar integrations as well (like scheduling!). Because there might need to be an extra authentication step, I'm thinking that we will need to use two different modals for this. After setting up the Penny Chat, the app should check for google calendar integration. If it doesn't exist for the user, invite them to add it and go through the OAuth flow of authorizing Google. After authorizing, they will be brought back into Slack, where they will be given the option of adding a Google Meet link to their chat. If they have already authorized google calendar, they will be brought straight to the last step. This is very similar to how Donut handles their Google calendar integration.

The plan is to:

• Set up the authentication flow
• Add a new "step" to the Penny Chat invitation asking to integrate g cal/asking to create a meet link
• Swap out the current calendar link on the invite to a link with the calendar event that the organizer has created
• Add the calendar link to the Penny Chat on the website, only visible if you are logged in

@JnBrymn @deadbender Any thoughts on this?

[ghost]

So the flow would look like this?

[JnBrymn]

That sounds about right to me @nchouard. Let's talk about it Tuesday.

[mrshwah]

In progress with PR #378