Add Tests

[codecov-commenter]

Codecov Report

Base: 66.07% // Head: 70.02% // Increases project coverage by +3.95% :tada:

Coverage data is based on head (a9c4f0c) compared to base (c0acaf4). Patch has no changes to coverable lines.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #51 +/- ## ========================================== + Coverage 66.07% 70.02% +3.95% ========================================== Files 18 18 Lines 840 844 +4 ========================================== + Hits 555 591 +36 + Misses 285 253 -32 ``` | [Impacted Files](https://codecov.io/gh/psrenergy/ToQUBO.jl/pull/51?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=psrenergy) | Coverage Δ | | |---|---|---| | [src/pbo/quadratization.jl](https://codecov.io/gh/psrenergy/ToQUBO.jl/pull/51/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=psrenergy#diff-c3JjL3Biby9xdWFkcmF0aXphdGlvbi5qbA==) | `72.54% <0.00%> (+1.96%)` | :arrow_up: | | [src/compiler/compiler.jl](https://codecov.io/gh/psrenergy/ToQUBO.jl/pull/51/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=psrenergy#diff-c3JjL2NvbXBpbGVyL2NvbXBpbGVyLmps) | `57.98% <0.00%> (+10.78%)` | :arrow_up: | 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=psrenergy). 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=psrenergy)

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