add get_timestamps to TimeSeries

[bendichter]

Motivation

What was the reasoning behind this change? Please explain the changes briefly.

How to test the behavior?

Show how to reproduce the new behavior (can be a bug fix or a new feature)

Checklist

• Did you update CHANGELOG.md with your changes?
• Have you checked our Contributing document?
• Have you ensured the PR clearly describes the problem and the solution?
• Is your contribution compliant with our coding style? This can be checked running flake8 from the source directory.
• Have you checked to ensure that there aren't other open Pull Requests for the same change?
• Have you included the relevant issue number using "Fix #XXX" notation where XXX is the issue number? By including "Fix #XXX" you allow GitHub to close issue #XXX when the PR is merged.

[codecov]

Codecov Report

Merging #1741 (4b8a2c4) into dev (ee86890) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##              dev    #1741      +/-   ##
==========================================
+ Coverage   91.96%   91.98%   +0.01%     
==========================================
  Files          27       27              
  Lines        2602     2606       +4     
  Branches      680      681       +1     
==========================================
+ Hits         2393     2397       +4     
  Misses        134      134              
  Partials       75       75              

Flag	Coverage Δ
integration	71.25% <25.00%> (-0.08%)	⬇️
unit	83.65% <100.00%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files Changed	Coverage Δ
src/pynwb/base.py	100.00% <100.00%> (ø)

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more

[rly]

Looks good. Please add a changelog.

Relatedly, could you also add to this PR (or a new PR) for data_in_volts = self.data * self.conversion + self.offset?