UHF on the 1D Hubbard model

[cjcscott]

This allows UHF calculations to be run on the 1D Hubbard model, where previously this resulting in an error when generating the initial guess density. This also updates various aspects of testing for Hubbard models while I was in there. Specifically

• Added test confirming unrestricted EWF calculation without spin-symmetry breaking on the 1D Hubbard model returns the same result as an equivalent restricted calculation.
• TestLattice.uhf() will now correctly return a LatticeUHF object.
• Reintroduced EDMET tests previously suspended due to #9, while also updating most tests in the same files to the new translational symmetry notation.

[codecov-commenter]

Codecov Report

Patch coverage: 52.94% and project coverage change: +0.15 :tada:

Comparison is base (bdb5622) 68.86% compared to head (05f84a6) 69.02%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #82 +/- ## ========================================== + Coverage 68.86% 69.02% +0.15% ========================================== Files 119 119 Lines 16854 16867 +13 Branches 2463 2466 +3 ========================================== + Hits 11607 11642 +35 + Misses 4531 4512 -19 + Partials 716 713 -3 ``` | [Impacted Files](https://codecov.io/gh/BoothGroup/Vayesta/pull/82?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BoothGroup) | Coverage Δ | | |---|---|---| | [vayesta/lattmod/latt.py](https://codecov.io/gh/BoothGroup/Vayesta/pull/82?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BoothGroup#diff-dmF5ZXN0YS9sYXR0bW9kL2xhdHQucHk=) | `83.74% <52.94%> (+4.85%)` | :arrow_up: | ... and [5 files with indirect coverage changes](https://codecov.io/gh/BoothGroup/Vayesta/pull/82/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BoothGroup) Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BoothGroup). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=BoothGroup)

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