Saving optim points in human format.

[nwittler]

What

The logfile that tracks the current best point in an optimization is more human-readable.

Why

Easier editing for humans.
Closes #139

How

• Changed the hjson call. Reading in these logs can already handle the new format.
• Added a test for loading from such a file
• Fixed a bug in the logreader to display a rich version of the log.

Checklist

Please include and complete the following checklist. Your Pull Request is (in most cases) not ready for review until the following have been completed. You can create a draft PR while you are still completing the checklist. Check the Contribution Guidelines for more details. You can mark an item as complete with the - [x] prefix

• Tests - Added unit tests for new code, regression tests for bugs and updated the integration tests if required
• Formatting & Linting - black and flake8 have been used to ensure styling guidelines are met
• Type Annotations - All new code has been type annotated in the function signatures using type hints
• Docstrings - Docstrings have been provided for functions in the numpydoc style
• Documentation - The tutorial style documentation has been updated to explain changes & new features
• Notebooks - Example notebooks have been updated to incorporate changes and new features
• Changelog - A short note on this PR has been added to the Upcoming Release section

[codecov]

Codecov Report

Merging #140 (72b7621) into dev (2b4625f) will decrease coverage by 0.01%.
The diff coverage is 90.47%.

@@            Coverage Diff             @@
##              dev     #140      +/-   ##
==========================================
- Coverage   71.43%   71.42%   -0.02%     
==========================================
  Files          36       36              
  Lines        5219     5217       -2     
==========================================
- Hits         3728     3726       -2     
  Misses       1491     1491              

Impacted Files	Coverage Δ
c3/utils/log_reader.py	62.22% <90.00%> (-1.61%)	⬇️
c3/optimizers/optimizer.py	81.94% <100.00%> (ø)

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[lazyoracle]

This looks pretty ready? What is pending in this?

[fedroy]

look good to me