Bug 1421111 - Use double digit hours in UI datetimes (#2994)
Bug 1421111 - Use double digit hours in UI datetimes (#2994)

This changes the times shown in the UI to be padded with a leading
zero if the hour is only a single digit (ie between midnight and 10am).
This fixes the test failure in `test_open_single_result()`, since
that expects the hour to use padding.
edmorley/treeherder,edmorley/treeherder,KWierso/treeherder,edmorley/treeherder,KWierso/treeherder,KWierso/treeherder,edmorley/treeherder,KWierso/treeherder