Remove --browser canary backwards-compatibility

[flotwig]

• Closes

User facing changelog

• n/a - part of earlier --browser changes

Additional details

n/a

How has the user experience changed?

--browser canary will not work in 4.x

PR Tasks

• Have tests been added/updated?
• Has the original issue been tagged with a release in ZenHub?
• Has a PR for user-facing changes been opened in cypress-documentation? cypress-io/cypress-documentation@648a08e

[cypress-bot]

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PR Review Checklist

If any of the following requirements can't be met, leave a comment in the review selecting 'Request changes', otherwise 'Approve'.

User Experience

• The feature/bugfix is self-documenting from within the product.
• The change provides the end user with a way to fix their problem (no dead ends).

Functionality

• The code works and performs its intended function with the correct logic.
• Performance has been factored in (for example, the code cleans up after itself to not cause memory leaks).
• The code guards against edge cases and invalid input and has tests to cover it.

Maintainability

• The code is readable (too many nested 'if's are a bad sign).
• Names used for variables, methods, etc, clearly describe their function.
• The code is easy to understood and there are relevant comments explaining.
• New algorithms are documented in the code with link(s) to external docs (flowcharts, w3c, chrome, firefox).
• There are comments containing link(s) to the addressed issue (in tests and code).

Quality

• The change does not reimplement code.
• There's not a module from the ecosystem that should be used instead.
• There is no redundant or duplicate code.
• There are no irrelevant comments left in the code.
• Tests are testing the code’s intended functionality in the best way possible.

Internal

• The original issue has been tagged with a release in ZenHub.

[cypress]

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Test summary

3634 • 0 • 46 • 0

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Run details

Project	cypress
Status	Passed
Commit	a3fefb6
Started	Feb 5, 2020 7:51 PM
Ended	Feb 5, 2020 7:57 PM
Duration	05:19 💡
OS	Linux Debian - 9.11
Browser	Multiple

View run in Cypress Dashboard ➡️

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[brian-mann]

I'll fix up the string concatenation to make it a little less fugly o_O in the 4.0 branch

[flotwig]

Released in 4.0.0.