E2E testing

[biern]

Well this involved much more work than I anticipated, but the initial setup is finally done.

• CI runs e2e tests on Chrome
• The actual build generated in the first step is used in e2e testing to make the process more robust and less time consuming
• Tests are runnable locally via npm or docker as well. See readme for that.
• The initial tests are pretty basic, just check if after uploading a file its hash and filename appear. They will get more sophisticated later on.

[jksf]

I wonder if we can have a single root for npm. Running separate npm install in tests/e2e directory is cumbersome. Can we add tests/e2e/package.json dependencies to dev-dependencies in the root project and remove package nesting?

[jksf]

To summarize, I appreciate this PR greatly :+1:. Issues that I commented are minor. I can make these changes myself if you are too busy.

[biern]

I wonder if we can have a single root for npm. Running separate npm install in tests/e2e directory is cumbersome. Can we add tests/e2e/package.json dependencies to dev-dependencies in the root project and remove package nesting?

I don't think that's a good idea. It will only create unnecessary dependencies between testing framework and the app itself that might eventually create further issues. I consider those a separate projects and would like to keep them that way.

[biern]

To summarize, I appreciate this PR greatly 👍. Issues that I commented are minor. I can make these changes myself if you are too busy.

Thanks! I can fix the remaining issues, but it probably won't happen soon as my schedule for the whole next week is full. In the meantime if you feel like working on that, feel free.

[biern]

I've fixed the remaining issues. I'm keeping the e2e tests as a separate npm project for now, we'll see how it performs.