Pep8 and pyflakes tidy of DB-API tests
Made the TimeFromTicks test work in all time zones

The TimeFromTicks and TimestampFromTicks tests used to only work if the
OS was set to a particular time zone. Now the time zone is explicitly
set to UTC at the beginning of the tests and so should always work.
Merge pull request #14 from tlocke/trunk

Merge test cleanup and fixes related to timezone sensitivity