Lower level unit tests for every QC criterion

[mirams]

We want an example of a trace to pass/fail each QC criterion, in the automated test suite.

[mirams]

Based on CSV files so they don't depend on other libraries to export code etc.

[kwabenantim]

To Do

• Review current tests
  • Fix possible bug in trace_after
• Double-check ranges/thresholds against paper (https://doi.org/10.1016/j.bpj.2019.07.029)
• Output number that failed/passed as well as pass/fail result.
• Add unit testing for each QC.
• Change data input from loading json files to loading pickled Trace objects #25

[frankiepe]

We may need to separate the Trace class from syncropatch_export so we don't rely on syncropatch_export. In the meantime, we will pickle the Trace objects and load them in, but continue to rely on syncropatch_export to manipulate the Trace objects once loaded.