Fix lint failures

Created by: rhelmer

I've found and fixed a few eslint errors, @bchivers-stanford the only part I am not 100% sure about is the adCssSelectors in the page-ads.js content script - I'm presuming that ad_css_selectors.js is imported implicitly somewhere?

Created by: bchivers-stanford

Thanks for doing all this!

adCssSelectors is submitted as a separate JS file to run before page-ads.js (see here). Should I be importing it in page-ads.js instead?

restored source branch github/fork/rhelmer/fix-lint-failures

restored source branch github/fork/rhelmer/fix-lint-failures

closed