Tests failing with Python 3.7

Hello, in the update to python3.7 rows is failint test with the message:

FAIL: rows.Table.add should be constant time

Traceback (most recent call last):
File "/builddir/build/BUILD/rows-0.3.1/tests/tests_table.py", line 318, in test_table_add_time
self.assertTrue(0.2 * mean > stdev)
AssertionError: False is not true

Ran 157 tests in 0.874s
FAILED (failures=1)
RPM build errors:
error: Bad exit status from /var/tmp/rpm-tmp.KIoK0X (%check)
Bad exit status from /var/tmp/rpm-tmp.KIoK0X (%check)
Child return code was: 1
EXCEPTION: [Error()]
Traceback (most recent call last):
File "/usr/lib/python3.6/site-packages/mockbuild/trace_decorator.py", line 89, in trace
result = func(*args, **kw)
File "/usr/lib/python3.6/site-packages/mockbuild/util.py", line 582, in do
raise exception.Error("Command failed. See logs for output.\n # %s" % (command,), child.returncode)
mockbuild.exception.Error: Command failed. See logs for output.

bash --login -c /usr/bin/rpmbuild -bb --target noarch --nodeps /builddir/build/SPECS/python-rows.spec

The issue is with the command

nosetests-3.7 -v -e tests_plugin_parquet -e tests_plugin_xlsx -e test_local_file_sample_size -e tests_plugin_json

References:

• Koji Build: https://koji.fedoraproject.org/koji/taskinfo?taskID=27753583
  Build Log: https://kojipkgs.fedoraproject.org//work/tasks/3583/27753583/build.log

Start with tests/tests_table.py at test_table_add_time, especially the assertion that rows.Table.add is constant time. Reproduce the failure with the reported nosetests-3.7 command and compare the timing behavior. Done means the test suite passes under Python 3.7 without weakening the intended performance check.