apps test suite

[fredrikbk]

The applications in the apps directory should be tested by simit-test. This means we should add an apps test suite that compiles the apps, and then runs them on small generated examples (e.g. a 3-chain or two tetrahedra). The results should be compared to golden results.

@gkanwar pointed out that we need something like this to guard against the issues @rennis250 ran into in #39.

The apps test suite replaces the current Program test suite, as there's no need to not bundle up all the programs and expose them to users.

Note that this does not test the C++ part of the example code, so we may also want add jenkins hooks to build and run those (and check results).