Add Transformation to set box dimensions

[hp115]

Fixes #2691

Changes made in this Pull Request:

• Add trajectory transformation for setting timestep dimensions

PR Checklist

• Tests?
• Docs?
• CHANGELOG updated?
• Issue raised/referenced?

[codecov]

Codecov Report

Merging #3175 (c50c604) into develop (62089a5) will increase coverage by 0.00%.
The diff coverage is 100.00%.

❗ Current head c50c604 differs from pull request most recent head 6b61a59. Consider uploading reports for the commit 6b61a59 to get more accurate results

@@           Coverage Diff            @@
##           develop    #3175   +/-   ##
========================================
  Coverage    92.73%   92.74%           
========================================
  Files          168      169    +1     
  Lines        22694    22713   +19     
  Branches      3218     3218           
========================================
+ Hits         21046    21065   +19     
  Misses        1600     1600           
  Partials        48       48           

Impacted Files	Coverage Δ
package/MDAnalysis/transformations/__init__.py	100.00% <100.00%> (ø)
...ackage/MDAnalysis/transformations/boxdimensions.py	100.00% <100.00%> (ø)

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[pep8speaks]

Hello @hp115! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file package/MDAnalysis/transformations/boxdimensions.py:

Line 73:24: E127 continuation line over-indented for visual indent
Line 79:24: E127 continuation line over-indented for visual indent

Comment last updated at 2021-04-06 15:03:50 UTC

[hp115]

Thank you for reviewing @tylerjereddy, I changed my files according to your suggestions.

[lilyminium]

Hi @hp115, thank you for working on this. I think it's getting close, but I have a few comments about structuring your errors, your tests, and the documentation. Please also address the PEP8 issues noted in by the bot.

You should check that the example you put in the documentation actually works, as these typos could have been easily caught.

[lilyminium]

Thanks @hp115, just fixed the merge conflict so tests can run.

[hmacdope]

LGTM @IAlibay @hp115. Aside from failing build.

As a side note @IAlibay @lilyminium (not in this PR) do we want to support setting the dimensions manually to an timesteps @ [a, b, c, alpha, beta, gamma] multidimensional array. Seems like something that could be useful?

[lilyminium]

Thanks @hp115, nearly there! As this is your first contribution to MDAnalysis, please add yourself to AUTHORS :-)

[lilyminium]

Thank you for adding this @hp115, it will be very useful!

[hp115]

Thank you @lilyminium, @IAlibay, @hmacdope and @tylerjereddy for your help and suggestions!