Add tests

[timokau]

It would be nice to be able to automatically test the cddlib package (make check and/or make installcheck). Since you already have examples, maybe just an automated way to verify those.

I tried running one example, but actually got a different result from the one in the repo. Maybe I did it wrong:

$ echo 3 | fourier cddlib/examples/project1.ine
...
Nonredundant representation:
H-representation
begin
 14 4 real
  2  0  0  1
  2  0  0 -1
  2  0  1  0
  2  0 -1  0
  2  1  0  0
  5  1  1  1
  5  1  1 -1
  5  1 -1  1
  5  1 -1 -1
  2 -1  0  0
  5 -1  1  1
  5 -1  1 -1
  5 -1 -1  1
  5 -1 -1 -1
end

Compared to https://github.com/cddlib/cddlib/blob/1ace54f514b705db4a838de514d80dbdcf7ed899/examples/project1res.ine