Python 3 renames StringIO -> io. Use six to deal
with this change.
Introduces new test dependency on six for StringIO.
Change-Id: Ia875b7fcbb976599053970ef79ed3f3474626bad
When a subunit stream for a testcase doesn't contain start end
enddate, the duration can't be calculated which leads to a:
ValueError: could not convert string to float
Check now if the duration is an empty string and add basic test
coverage based on ddt for the subunit_trace command.
Change-Id: I9953019794ba53fcfcb20e32fecbe94da22c9565
This commit adds some basic unit tests which runs ostestr in some
basic configurations against a fake test suite to ensure that the
ostestr always exits with a 0 on success and 1 on errors when running
tests. This is invaluable for using ostestr in ci systems.
