Add chime icon handle and timezone config option

[goldhand]

This adds a aws chime icon when that is in the meeting url.

It also adds a config for time_zone, so if the system isn't working (mine wasn't) users can manually specify a time zone.

I also changed:

if online_meeting == u'true' and body_html:
    # handle online meeting url

to

if body_html:
    # handle online meeting url

Because that event.is_online_meeting was returning false for me when all I have are online meetings now days lol. Not sure what that prevented anyway.

Note: I changed some other things (eg tconf instead of tc but that's not in PR, also blocked out my server uri in screenshot

This also fixes the regex example in readme.

[jeeftor]

Can you update the MR and I'll pull it in.

I no longer use this plugin but happy to release a new version for those that do.

[goldhand]

Just fixed it! Yeah it's awesome actually, I love it

[jeeftor]

Just merged this in - I'll try to get a new release pushed up to GitHub -> however as I no longer use the repo if you wanted I could transfer it over to you?

[jeeftor]

and/or make you a collaborator