Switch from npm to yarn

[Turbo87]

As discussed in the meeting on friday, yarn currently has better UX and allows us to use resolutions to work around transitive dependency version conflicts. This should unblock #2699, for example.

r? @jtgeibel

[bors]

☔ The latest upstream changes (presumably #2903) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[bors]

☔ The latest upstream changes (presumably #2909) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[jtgeibel]

LGTM, but needs to be updated for #2909. Feel free to r=me after that.

[Turbo87]

@bors r=jtgeibel

[bors]

📌 Commit 7e9f0bc has been approved by jtgeibel

[bors]

☔ The latest upstream changes (presumably #2892) made this pull request unmergeable. Please resolve the merge conflicts.

Note that reviewers usually do not review pull requests until merge conflicts are resolved! Once you resolve the conflicts, you should change the labels applied by bors to indicate that your PR is ready for review. Post this as a comment to change the labels:

@rustbot modify labels: +S-waiting-on-review -S-waiting-on-author

[bors]

🔒 Merge conflict

This pull request and the master branch diverged in a way that cannot be automatically merged. Please rebase on top of the latest master branch, and let the reviewer approve again.

How do I rebase?

Assuming self is your fork and upstream is this repository, you can resolve the conflict following these steps:

1. git checkout yarn (switch to your branch)
2. git fetch upstream master (retrieve the latest master)
3. git rebase upstream/master -p (rebase on top of it)
4. Follow the on-screen instruction to resolve conflicts (check git status if you got lost).
5. git push self yarn --force-with-lease (update this PR)

You may also read Git Rebasing to Resolve Conflicts by Drew Blessing for a short tutorial.

Please avoid the "Resolve conflicts" button on GitHub. It uses git merge instead of git rebase which makes the PR commit history more difficult to read.

Sometimes step 4 will complete without asking for resolution. This is usually due to difference between how Cargo.lock conflict is handled during merge and rebase. This is normal, and you should still perform step 5 to update this PR.

Error message

Removing package-lock.json
Auto-merging .travis.yml
CONFLICT (content): Merge conflict in .travis.yml
Auto-merging .github/workflows/ci.yml
CONFLICT (content): Merge conflict in .github/workflows/ci.yml
Automatic merge failed; fix conflicts and then commit the result.

[Turbo87]

@bors r=jtgeibel

[bors]

📌 Commit 68dfee5 has been approved by jtgeibel

[bors]

⌛ Testing commit 68dfee5 with merge 2045973...

[bors]

☀️ Test successful - checks-travis
Approved by: jtgeibel
Pushing 2045973 to master...