Returns the current status of London Underground lines using TfL's open data as an Actions on Google App

If this fails with something like:

Error: getaddrinfo ENOTFOUND cloud.tfl.gov.uk cloud.tfl.gov.uk:80
    at errnoException (dns.js:28:10)
    at GetAddrInfoReqWrap.onlookup [as oncomplete] (dns.js:76:26)

it's because you're on the Firebase Spark plan, which doesn't support external non-Google services. Enter your billing details and upgrade to the Blaze plan to access use them (which is still free, as long as you don't use more than the pretty high limits)

This software is licensed under the MIT License. Hopefully you can learn and develop from it - please do send pull requests if you think you've improved it in some way (however small, it's really appreciated).