Add more regions to launch solution

[ferdingler]

So far this solution can be launched in 3 regions: us-east-1, us-east-2 and us-west-2. The reason is because at the moment of writing it, Fargate was not available in all regions. However it is now available in much more.

Supporting more regions on this project is easy:

1. Make sure all services used in the project are available in the desired regions.
2. Change the template located in cloudformation/fargate-vpc.yaml to add the availability zones corresponding to each region in the RegionMapping field.
3. Update README file to add buttons to launch on the additional regions.