bug: fix data to string from buffer for output channel

[eleanorjboyd]

output from the testing run being printed as buffer not string for the testing rewrite.

[Tyriar]

Can you provide some steps for a Python noob to verify this?

[eleanorjboyd]

1. create a test with print output
2. have the test be one that fails
3. run the test
4. check "python test logs"
5. make sure you can read the output

def test_add():
    print("text here,text here,text here,text here,text here,")
    assert add(1,2) == 4