Update or remove Implicit Flow branch

[jeroenheijmans]

Someone let us know that the implicit-flow branch is broken at the moment.

The implicit-flow branch relies on demo.identityserver.io which recently removed the implicit client completely.

Three options:

• remove the implicit flow branch
• update the branch to use another demo IDS
• update the branch to warn the user to configure their own IDS

[jeroenheijmans]

Linked issue reported a similar problem, turned out the master branch also needed a fix.

Pushed one for master this morning, but the implicit-flow still needs work. That client was completely deleted from the IDS that I was using, and the "API calls" the app makes rely on that same IDS (so cannot just change the config, this branch needs some more work).

[jeroenheijmans]

Perhaps "archiving" the branch is the way to go?