Remove selenium and phantomjs

[jantman]

Since PhantomJS seems broken on Alpine Linux, consider removing PhantomJS and Selenium from the Docker images, then updating docs on how to run them locally or in a separate container. We'd also need to add an API for wishlist2project, because that uses selenium too.

[jantman]

Alpine Linux has chromium and chromedriver packages. It's big, 208MB installed, whereas right now our whole image is only 333MB. But it would give us a working browser inside the Docker image for wishlist and custom scraper-based ofxgetter classes.

Perhaps we should start building and publishing -chrome Docker images, built FROM the normal ones.