Remove zero length field names in format

Python older than 2.7 need to have a field name in the format
strings so this "Test {}".format(variable) needs to either use
keyword arguments and names or numbers for arguments:

"Test {test}".format(test=variable) or
"Test {0}".format(variable)
Patch version 0.4.2

* Formatting error fixed on python versions older than 2.7