Add additional tests on views

[geekygirlsarah]

What GitHub issue does this PR apply to?

Resolves #691

What changed and why?

Added a variety of tests:

• Check only GET is allowed
• Check friendly names of languages/concepts don't pass
• Check a reverse on a URL that doesn't exist raises exception

Also force all pages to only allow GET methods.

Checklist

• I claimed any associated issue(s) and they are not someone else's
• I have looked at documentation to ensure I made any revisions correctly
• I tested my changes locally to ensure they work
• For language files, I have validated the edited files are valid JSON and data shows up correctly
• For website code edits, I have added or edited any appropriate unit tests for my changes