Remove package-lock.json for now

[dbkr]

As per element-hq/element-web#7083

The package-lock file is currently not bringing any of the benefits
it's supposed to bring because we don't do the neccessary things to
massage it during the release process. Remove it until we actually
manage it correctly.

[bwindels]

Cool. Perhaps also include it in .gitignore?

[dbkr]

Done

[bwindels]

The GroupView tests are broken, hmm. Doesn't seem like it's due to test flakiness as I restarted the build with exactly the same result.

[dbkr]

Eugh, presumably, having asserted npm isn't reading this file, presumably npm 6 on Travis is reading it and is preventing us from pulling in a new dependency which breaks the test. What a mess.

[bwindels]

Interesting. Strange that adding it to .gitignore would trigger this. Seems to be a TypeError in the client (or the peg), in one of the fetchers in GroupView::_resourceFetcher. Would be good to see the stack. Ughh.

[bwindels]

sanitize-html seems to be the offender. Adding it to .gitignore was probably not what caused the error but merging the PR in riot-web as it's in the manifest for both repos (with different versions)

[dbkr]

indeed it did seem to be the sanitize-html thing