Refactor exception message generation

Code to stringify the exception's fields was in the wrong place
Change the schema for live databases

Now records the database name instead of using the id as the database name

user and password would depend on the dump being loaded into it.
Eliminate an exception decoding empty JSON - the test now passes cleanly
templates and databases now have owners - this will be necessary to re-create them from dumps
Forgot trailing quote
Abstract out the application configuration

Tests can now supply their own configuration object

file_storage_path is now handled by the configuration
Class to create and drop Postgres database instances
Merge pull request #2 from amb43790/develop

Develop