Updating .travis.yml to allow postgres testing
Adding PostgreSQL regression tests
Simplifying .travis.yml now that I understand how to test locally
Add debugging lines to figure out why local tests work but Travis fails
Remove debugging lines.

Looks like Travis failure may have been a fluke?
Remove redundancy from regression test code

There was a copy of the for loop code for each database management
system. This uses a nested loop to avoid this issue.
Merge pull request #131 from ethanwhite/dry-regr-tests

DRY out the regression tests