Use the new Azure "Fluent" logo

[roel4ez]

I love this repo as it is a good and helpful resource to get icons for diagram easily and without hassle. Great work!

Azure has a new logo: https://azure.microsoft.com/en-in/blog/a-fluent-new-look-for-the-azure-icon/, svg can be found here: https://en.wikipedia.org/wiki/File:Microsoft_Azure.svg

It would be great if that one could be added to the list.

I'm happy to submit a PR, just not sure where it all has to be changed (png and svg are easy enough to find, but not sure if there are any sprites that need updating)

Thanks!

[travisnielsen]

Icon fixed in #37