1) test_python_exists. Fail if python3 isn't in PATH.
2) test_python_stdout. Run a Python script and check the output is as expected
3) test_python_testfile. Check that a file test_python_stdout wrote to exists.
(1) should be a setup and skip the test module if it isn't present.
(2) and (3) should be merged, there's no point copying over a two line Python
file, and the test doesn't verify that the file doesn't exist in the first
place.
Rewrite the test to check that Python is present in a class setup so the entire
test is skipped if it isn't and do some simple rot13 to verify that bytecode is
being executed correctly.
Signed-off-by: Ross Burton <ross.burton@intel.com>