try out typescript-eslint

[cyberhck]

from recent news, tslint will be deprecated in favor of typescript-eslint and community has started moving to that package. We can make a list of rules we're using, and check them off once they're migrated, (if something's not migrated, we can send them PR), our custom rules also might be ported as well :)

Not every rule has been ported, maybe we can use both at once? At least the indentation rule might work.