Merge test-including default-template

[inaimathi]

This is a more elaborate default-template that

1. Includes separate src and test directories
2. Includes a shell script that runs the test suite in sbcl
3. Includes a .travis.yml file that allows the project to be trivially built in CI

I'm mainly submitting this because of inaimathi/house@262ceba#r45065608 (which tells me that it might be a good idea in general to standardize project structure because there are non-obvious ways to mess it up).

The points of contention I can see are related to the default choices (Should we use prove? Should we use travis? Should we assume sbcl?).

Overall:

1. The defaults can be overriden as always (that was the point of the default-template addition :p)
2. encouraging and simplifying testing/CI is worth picking reasonable but somewhat arbitrary defaults
3. A plurality of the CL community seems to use sbcl in any case

[diasbruno]

This is a specific runner. Maybe it could be another template directory?