upgrade to ember-cli 3.20 and other dependencies

[nickschot]

Makes #74 unnecessary.

Ideally we need ember-showdown-prism to be released with empress/ember-showdown-prism#4 so we dont have to rely on the branch version. done, PR updated.

Needs #76 to build properly. updated

Edit: This was originally including #77 but @mansona split that out into a separate PR 👍

[nickschot]

Not entirely sure why netlify's build is failing with the weird ember-data error. Might be a cache thing. I don't have the power to restart the build.

EDIT: also ran into this locally just now. Seems indeed to be a caching issue as removing node_modules & npm i fixes it. See also: emberjs/data#7221

[nickschot]

So indeed, tests work, netlify needs its node_modules cache to be deleted.

[mansona]

so... I had to rebuild the Netlify because it failed originally, but now it is passing but throwing a strange error in the build for some of the pages 🤔 TypeError: Cannot read property 'rest' of undefined any ideas? https://app.netlify.com/sites/empress-blog-ember-template/deploys/5f3aa5d8ad43c451b3a78e84

[nickschot]

Yes this is what I made the other PR for in the showdown-prism repo. This error happens when you pass a language to the markdown codeblock which isn't supported by prism or it's config. I replaced the "sh" occurrences with bash already, maybe I missed some more?

EDIT: The "dummy" content indeed also contains hbs (should be handlebars) and yaml which was not included as a plugin. I added a configuration to this for now which also includes yaml. Also created a PR for ember-showdown-prism to include yaml by default. If you agree with that we can remove the configuration from this PR again.

[mansona]

looks good 👍