spike: drivers license parsing

[adamdecaf]

TODO: some docs/notes on parsing PDF417 barcodes (which are common on the back of a drivers license)

• https://github.com/zxing/zxing/blob/master/core/src/main/java/com/google/zxing/pdf417/PDF417Reader.java
• https://github.com/makiuchi-d/gozxing
• https://github.com/ksoftllc/license-parser/blob/master/LicenseParser/Classes/LicenseParser.swift
• https://github.com/c0shea/IdParser
• https://en.wikipedia.org/wiki/PDF417

Issue: moov-io/paygate#169