Ciborg can now be created in any AWS region.

Having Ciborg in a user defined AWS region is better for
latency and data sovereignty.

The default region is Northern Virginia (us-east-1).

There is no default availabilty zone; instead let AWS decide
the most suitable AZ.
Fix broken build and added a test
Merge pull request #6 from srbartlett/master

Ciborg can now be created in any AWS region.