Allow changing the DSN after configuration

[mike-zorn]

Addresses #650.

@benvinegar, I just made this quickly in the github editor to better explain what I meant, so excuse any errors: this isn't ready for merge. Does this approach seem reasonable?

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This change is

[benvinegar]

Yeah this seems reasonable, although could you change it to setDSN to match the private method _parseDSN?

[mike-zorn]

@benvinegar I've updated the PR to make the naming consistent and add a test. Let me know if it's acceptable.

[benvinegar]

It would be nice if this could be done via config (i.e. call config a second time) so we wouldn't have to introduce another API method, but ... it's unclear what would happen to your previously set configuration (e.g. does it reset to defaults). I can see a case where just being able to toggle the DSN, free of other side effects, is useful. So going ahead w/ merging.

[benvinegar]

Reviewed 2 of 2 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved.

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