allow setting port in tests

[mringler]

Allows to run tests on different ports using the DB_PORT environment variable

Had to update InitCommandTest as it parsed the DSN string by value position instead of by key

[codecov-commenter]

Codecov Report

Base: 73.25% // Head: 73.25% // No change to project coverage :thumbsup:

Coverage data is based on head (693683e) compared to base (b542279). Patch has no changes to coverable lines.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1923 +/- ## ========================================= Coverage 73.25% 73.25% Complexity 7917 7917 ========================================= Files 227 227 Lines 21133 21133 ========================================= Hits 15480 15480 Misses 5653 5653 ``` | Flag | Coverage Δ | | |---|---|---| | 5-max | `73.25% <ø> (ø)` | | | 7.4 | `73.25% <ø> (ø)` | | | mysql | `68.95% <ø> (ø)` | | | pgsql | `69.05% <ø> (ø)` | | | sqlite | `66.96% <ø> (ø)` | | 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=propelorm#carryforward-flags-in-the-pull-request-comment) to find out more. 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=propelorm). 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=propelorm)

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