strip URLs from name/address

[missinglink]

as suggested in pelias/polylines#280 (comment) this PR strips URLs from name/address strings within the Model module itself.

Discuss!

related #115

[missinglink]

Originally I thought it would be better to have this functionality in the importers but doing it in each has become arduous.

There have been a lot of people opening issues regarding all these warnings during import, which I'd like to avoid.

Any documents which contained a URL were being dropped, this would allow them to be saved.

It's hard to strip URLs (cleanly), in the test cases you'll see that if there is no whitespace after the URL then the extra chars are considered part of the URL.

It's also hard to avoid double-spaces, although I don't think this is an issue.

[orangejulius]

Yeah I think this is a good, practical change.

I'm still not 100% sure on where we put logic that should be common across all importers. Model is a bit unwieldy for many things, but it's the best we have for now.