Smart phone number creation

[switzersc]

When we collect phone data from organizations, services, and locations, we're taking the whole field and putting it in the number column in the output phones.csv. This is a problem because the phone field might actually include extensions or other text. It would be great to at least parse out extensions in the number column and move them to the extension column.

See examples in this fixture: https://github.com/switzersc/open_referral_transformer/blob/master/spec/fixtures/output/resources/phones.csv

[switzersc]

Started with #33