instead of deprecated microsecond property setter.

Add test for round-to-next-second branch.

Applied the same fix to the trim logic in method
TimeseriesUtility.pad_and_trim_trace() as previously applied
to the pad logic. Added a unit test that would have failed
using the old logic.

The first attempt to fix TimeseriesUtility.pad_and_trim_trace() broke
a unit test. I'm not sure I agree with what the unit test defined as
passing, but I do understand the logic. This now satisfies the logic
of the unit test(s), while still fixing the floating point precision
problem to the default resolution of UTCDateTime objects (that is,
1e-6 or microseconds)

I ran into a floating point precision issue when padding a trace out
to the requested starttime when the data block returned by the Edge
miniseed factory (but this is not an Edge issue, per se) was less
than what was requested.

My solution was to use `round()` instead of `int()` when converting
a time differential to a discrete number of samples. I'm confident
this is a robust fix for padding. I'm not sure if it also the proper
approach to the trimming, which seems to be a bit more sophisticated
in that is uses the `ceil()` method. In any case, I request some
feedback before merging this deceptively simple PR.

Jeremy M Fee authored 6 years ago and Claycomb, Abram Earl committed 6 years ago

Add "without_gaps" option to get_stream_start_end_times, add "pad_and_trim_trace" method and update pad_timeseries to use it

ObsPy/NumPy have a bug related to masked arrays that this small
change works around by forcing gaps to be filled by NaNs, even
during intermediate processing.

Fixed some linting errors and made the merge_streams() code cleaner as well as added more unit testing

Cleaned up merge_stream(), takes empty channels out at the beginning and adds them in before the merge() function