Update phpunit/phpunit from 7.5.15 to 7.5.16

[violinist-bot]

If you have a high test coverage index, and your tests for this pull request are passing, it should be both safe and recommended to merge this update.

Here is a list of changes between the version you use, and the version this pull request updates to:

• 316afa688 Prepare release
• d434b3307 Fix issues identified by Psalm
• 2400d7995 Enhancement: Use built-in PHP 7.3 to speed up build
• 191e0342f Keep php-cs-fixer from removing or simplifying "return null;"
• 046ebede3 Fix issue identified by Psalm
• c5ef03407 Cleanup
• 368b5bc41 Throw meaningful exception in TestSuiteIterator.getChildren()
• 7ed7374d4 Fix issue identified by Psalm
• 15bb615e3 Document the fact that $suite->tests() only contains TestCase objects at this point
• f9869c48b Rename variable
• cb87c2680 Use addcslashes() for Fix trailing slash in XdebugFilterScriptGenerator - closes #3834 sebastianbergmann/phpunit#3835 (comment)
• 72098d80f Reject non-iterable parameter groups
• 2d1e3990c Improve the TestSuite.tests getter/setter type annotations
• f7f47936e Make the return type of TestSuiteIterator.current nullable
• 002c0e26e Closes #3834
• da34f4f8f Marker interfaces for exception should extend Throwable
• 7fdbf5cb2 Properly initialize TestSuiteIterator.position
• 4f201f737 Add tests for TestSuiteIterator
• c0f5ff20c Fix: Rename job
• ba982b6a8 Enhancement: Run php-cs-fixer as GitHub action
• b9100692a add test for --generate-configuration command
• 7aee97012 Enhancement: Configure indentation for YML files in .editorconfig
• 957c1ee1c Make .travis.yml warning-free
• ec19f169c Added tests for the --columns command line argument
• 928b6e547 Update tools
• 1a0669f90 Update ChangeLog
• 78e3d056f Export constants values when mocking method

---

This is an automated pull request from Violinist: Continuously and automatically monitor and update your composer dependencies. Have ideas on how to improve this message? All violinist messages are open-source, and can be improved here.

[codecov-io]

Codecov Report

Merging #140 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             master   #140   +/-   ##
=======================================
  Coverage       100%   100%           
  Complexity        4      4           
=======================================
  Files             2      2           
  Lines            19     19           
=======================================
  Hits             19     19

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 330ad29...bfb67e1. Read the comment docs.