Force custom reporters to use bundled mocha version

[kuceb]

• force custom reporters to use our bundled mocha, which means users no longer need to install mocha to satisfy mocha reporter peer dependencies
• remove npmInstall logic in helper/e2e script

details:

• this is tested by changing some of our e2e test script logic to use mocha 7.x, which would normally fail.
• this should be a bugfix

docs changes:

• need to remove instructions to add mocha as a devDependency since the mocha reporter will be forced to use our bundled mocha
  

• fix TypeError when using custom reporter #3537 issue with custom reporters
• fix use mocha 7.0.1 in packages/server #6984 bump packages/server mocha version

User facing changelog

• Bug Fix: Custom mocha reporters will now correctly use the version of mocha bundled with Cypress

Additional details

How has the user experience changed?

PR Tasks

• Have tests been added/updated?
• Docs PR docs for use-bundled-mocha-for-reporters cypress-documentation#2701
• Has the original issue been tagged with a release in ZenHub?

[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

7182 • 0 • 98 • 0

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Run details

Project	cypress
Status	Passed
Commit	3f1cb80
Started	Apr 22, 2020 3:50 AM
Ended	Apr 22, 2020 3:55 AM
Duration	05:44 💡
OS	Linux Debian - 10.1
Browser	Multiple

View run in Cypress Dashboard ➡️

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[flotwig]

so the main benefit of this PR is they don't need to install mocha to use a custom reporter, right?

is there a docs PR?

[flotwig]

is there a docs PR?

[kuceb]

ok, fixed the spec globbing issue...finally

[kuceb]

note the docs PR