Update phpunit/phpunit requirement from ^4.8.6 to ^8.3.4

[dependabot-preview]

Updates the requirements on phpunit/phpunit to permit the latest version.

Changelog

Sourced from phpunit/phpunit's changelog.

8.3.4 - 2019-08-11

Changed

• Implemented #3788: Cast exception message to string

Fixed

• Fixed #3772: Process Isolation does not work when PHPDBG is used

8.3.3 - 2019-08-03

Fixed

• Fixed #3781: MockBuilder::addMethods() and MockBuilder::onlyMethods() do not handle empty parameter array correctly

8.3.2 - 2019-08-02

Fixed

• More work on the fix for #3774: Restored name of PHPUnit\Framework\Error\Deprecated

8.3.1 - 2019-08-02

Fixed

• Fixed #3774: PHP errors, notices, etc. cannot be tested anymore with PHPUnit 8.3

8.3.0 - 2019-08-02

Added

• Implemented #3687: Introduce MockBuilder::addMethods() and MockBuilder::onlyMethods() as alternatives to MockBuilder::setMethods()
• Implemented #3741: Format class names as well as method names in TestDox output
• Implemented #3748: Add option to sort tests based on information from @small, @medium, and @large
• Added TestCase::getActualOutputForAssertion() as a wrapper for TestCase::getActualOutput() to prevent a test being marked as risky when it prints output and that output is not expected using TestCase::expectOutputString() or TestCase::expectOutputRegEx()

Changed

• Implemented #2015: Prefix all code bundled in PHAR distribution with random/unique namespace
• Implemented #3503: The error handler has been refactored to not rely on global state
• Implemented #3521: The @errorHandler annotation, which controlled a feature that was not documented and did not work correctly, does not have an effect anymore
• Implemented #3522: The TestCase::setUseErrorHandler() method, which controlled a feature that was not documented and did not work correctly, has been deprecated and does not have an effect anymore
• Implemented #3687: MockBuilder::setMethods() is now deprecated

... (truncated)

Commits

• e31cce0 Prepare release
• e06998a Delete old ChangeLog files
• 0a41696 Update ChangeLog
• b8ff3c1 Fix CS issue
• bfdfbe1 Fix whitespace issue
• 052b0d3 Cast exception message to string
• bfd98d0 Update ChangeLog
• dc2365b Revert "Enable strict interpretation of scalar type declarations"
• c319d08 Prepare release
• 05ef7ae Restore annotation
• Additional commits viewable in compare view

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[dependabot-preview]

Superseded by #7.