allow either (<time> seconds) or (<time>s) format for test result time

Summary: The default Go Test Parser stopped showing the test function name at the end of the package after some Go upgrade. We fixed it locally and wanted to share it upstream.

Test Plan: We ran it on our test suite using go1.4.2 darwin/amd64. We have version-dependent code which cannot be compiled with earlier versions of Go, unfortunately.

Reviewers: Blessed Reviewers, epriestley

Reviewed By: Blessed Reviewers, epriestley

Subscribers: avivey, Korvin, epriestley

Maniphest Tasks: T7845

Differential Revision: https://secure.phabricator.com/D12436