Store exceptions

[dentarg]

I think it could be a good idea to store the exceptions that Twingly::URL swallow. It might be useful to know why a particular wasn't valid, as the list of exceptions we rescue will likely grow.

We could expose .exceptions, just like MetaInspector does: https://github.com/jaimeiniesta/metainspector#exception-handling (we already have the ok? equivalent in valid?)

WDYT @twingly/dev?

Somewhat related to #44, #31, #25

[jage]

Sure, this would be a very good feature to have if/when we capture all unhandled exceptions. #31 should probably be solved before or at the same time as this.

[dentarg]

Just want to note that MetaInspector might remove their exception log: jaimeiniesta/metainspector#154

[dentarg]

I don't think this is worth the effort. Close as wontfix?

[walro]

Works for me.