Trivial test suite

[baziotis]

It's pretty obvious that we need a test suite. I was thinking a very trivial test suite, where basically we just have a /tests folder with .cpp files. Every file in this folder should have a first line denoting how it should be compiled. Then, we run a script that for every file, reads its first line, compiles it and runs it. If we have an assert, then the test failed.