Adding identity print output to test

[benedictpaten]

As a simple test of correctness, it would be helpful if each test in tests/test.py that creates a sam file were to report the avg. identity / avg. coverage / total number of alignments in the sam file.

[benedictpaten]

It would also be good if each test reported how long it took to run marginAlign(Call), so that we can do some basic performance evaluation.

[benedictpaten]

Done.