Add Travis Tests

I think this is all pretty much straightforward. Results of a passed run are at https://travis-ci.org/rocky/datacache

I also added a GNU Makefile using [remake](http://bashdb.sourceforge.net/remake/) comments which are in-passing explained [here](http://bashdb.sourceforge.net/remake/).  I added that mostly because I needed something to kick off an automated test from a commit. Feel free to remove the Makefile.