Update xstream to version 9.0.0 🚀

[greenkeeperio-bot]

Hello lovely humans,

xstream just published its new version 9.0.0.

State	Update 🚀
Dependency	xstream
New version	9.0.0
Type	devDependency

This version is not covered by your current version range.

Without accepting this pull request your project will work just like it did before. There might be a bunch of new features, fixes and perf improvements that the maintainers worked on for you though.

I recommend you look into these changes and try to get onto the latest version of xstream.
Given that you have a decent test suite, a passing build is a strong indicator that you can take advantage of these changes by merging the proposed change into your project. Otherwise this branch is a great starting point for you to work on the update.

Do you have any ideas how I could improve these pull requests? Did I report anything you think isn’t right?
Are you unsure about how things are supposed to work?

There is a collection of frequently asked questions and while I’m just a bot, there is a group of people who are happy to teach me new things. Let them know.

Good luck with your project ✨

You rock!

🌴

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The new version differs by 13 commits .

• 747eae1 chore(package): release new version
• f22f09c docs(README): update FAQ a bit
• b8d6995 fix(flattenSequentially): stop execution of interrupted inner streams
• 90ca395 test(imitate): fix test for imitate error propagation
• e512c3e fix(stream): throw error when there are no error listeners
• 7327a9d test(flattenConcurrently): fix flattenConcurrently test for node.js too
• 248c495 docs(README): updated TOC template to not generate extra newlines
• f7aa61c test(browser): introduce browser tests
• cf35f4b chore(package): release new version
• 94f3bdc test(flattenSequentially): add test checking stop() clean ups
• fd31d49 fix(flattenSequentially): fix behaviour of outer stream completion
• a07e5c9 docs(README.md): update listener to only require next
• 1d6c923 chore(package): make this ComVer-compliant

See the full diff.

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This pull request was created by greenkeeper.io.

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