Add more tests to improve coverage

[codecov[bot]]

Codecov Report

Base: 91.65% // Head: 93.66% // Increases project coverage by +2.01% :tada:

Coverage data is based on head (8a60f4f) compared to base (2d50287). Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #8 +/- ## ========================================== + Coverage 91.65% 93.66% +2.01% ========================================== Files 38 38 Lines 1594 1595 +1 ========================================== + Hits 1461 1494 +33 + Misses 133 101 -32 ``` | [Impacted Files](https://codecov.io/gh/sancane/rustun/pull/8?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio) | Coverage Δ | | |---|---|---| | [stun-rs/src/attributes/turn/data.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvYXR0cmlidXRlcy90dXJuL2RhdGEucnM=) | `100.00% <ø> (+19.04%)` | :arrow_up: | | [stun-rs/src/attributes/turn/requested\_transport.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvYXR0cmlidXRlcy90dXJuL3JlcXVlc3RlZF90cmFuc3BvcnQucnM=) | `100.00% <ø> (+9.52%)` | :arrow_up: | | [stun-rs/src/attributes/unknown.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvYXR0cmlidXRlcy91bmtub3duLnJz) | `100.00% <ø> (+35.00%)` | :arrow_up: | | [stun-rs/src/message.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvbWVzc2FnZS5ycw==) | `97.33% <ø> (ø)` | | | [stun-rs/src/registry.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvcmVnaXN0cnkucnM=) | `92.85% <ø> (+7.14%)` | :arrow_up: | | [stun-rs/src/types.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvdHlwZXMucnM=) | `98.30% <ø> (+12.71%)` | :arrow_up: | | [stun-rs/src/attributes/address\_port.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvYXR0cmlidXRlcy9hZGRyZXNzX3BvcnQucnM=) | `98.05% <100.00%> (+0.70%)` | :arrow_up: | | [stun-rs/src/strings.rs](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio#diff-c3R1bi1ycy9zcmMvc3RyaW5ncy5ycw==) | `94.44% <100.00%> (+3.37%)` | :arrow_up: | | ... and [4 more](https://codecov.io/gh/sancane/rustun/pull/8/diff?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Santiago+Carot-Nemesio) | | 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=Santiago+Carot-Nemesio). 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=Santiago+Carot-Nemesio)

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