Allow saving coordinate trajectory on disk

[shoubhikraj]

---

TODO

• [x] make history work with bracket methods
• [x] change the tests to be more consistent

Checklist

• [ ] The changes include an associated explanation of how/why
• [ ] Test pass
• [ ] Documentation has been updated
• [ ] Changelog has been updated

[shoubhikraj]

@t-young31 Please ignore all the errors in the tests - i don't want to go through the effort of modifying the tests in case changes are needed in the main code.

[t-young31]

had a quick scroll through and all looks very sensible to me. added one tiny comment along the way

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 99.33185% with 3 lines in your changes are missing coverage. Please review.

Project coverage is 97.38%. Comparing base (0076016) to head (c683ad1).

Files	Patch %	Lines
autode/bracket/ieip.py	91.42%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## v1.4.3 #329 +/- ## ========================================== - Coverage 97.45% 97.38% -0.07% ========================================== Files 209 200 -9 Lines 23774 23064 -710 ========================================== - Hits 23168 22461 -707 + Misses 606 603 -3 ``` | [Flag](https://app.codecov.io/gh/duartegroup/autodE/pull/329/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=duartegroup) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/duartegroup/autodE/pull/329/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=duartegroup) | `97.38% <99.33%> (-0.07%)` | :arrow_down: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=duartegroup#carryforward-flags-in-the-pull-request-comment) to find out more.

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[shoubhikraj]

@t-young31 Hi, when you have time, could you please take another look at this?