Added verbose output, spinner instead of '.'

[michielvg]

Thank you for the work and the test framework.

I had a bit of tests to run and the printf(".") did not do it for me.
So I added a printf per test to know what test was running and a spinner to show progress.
There are some magic numbers, like the update every 200 asserts, but for now it does the trick.

example output:

Running test: test_le_host_conversions
✓ - 10
Running test: test_be_host_conversions
✓ - 10 
Running test: test_roundtrip_properties 
✓ - 131084
Running test: test_read16
✓ - 512 
Running test: test_read32
✓ - 10
Running test: test_write16
✓ - 1024
Running test: test_write32
✓ - 40
Running test: test_buffer_roundtrip
✓ - 8