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* Adds CV_time and CV_current summary stats - Thanks Dan Cogswell!
* Tolerances for CV segment extraction are now input variables.
* Adds dtypes for CV_time and CV_current.
* CV time stat now set to None for cycles which don't have charge steps.
* Adds CV_time and CV_current as summary stats, and a helper function to extract the CV portion of charge.
* Converts test_time from float32 to float64. It can get large enough that decimal points are truncated with float32, producing data points with exactly the same test_time.
* Add file copy to test so that generation can run automatically
* Working version of intracell features - thanks Patrick Asinger!