Tests: Add trace reading test with babeltrace bin

This test uses the sample traces found in tests/ctf-traces and the
babeltrace cli tool to parse them. The traces found in
ctf-traces/succeed should return a successful exit code and those in
ctf-traces/fail should return a failure exit code.

Signed-off-by: Christian Babeux <christian.babeux@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>