Bump phpunit/phpunit from 7.5.3 to 7.5.4

Bumps [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) from 7.5.3 to 7.5.4.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-7.5.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/compare/7.5.3...7.5.4)

Signed-off-by: dependabot[bot] <support@dependabot.com>

composer.lock

@@ -4429,7 +4429,7 @@
                 },
                 {
                     "name": "Gert de Pagter",
-                    "email": "backendtea@gmail.com"
+                    "email": "BackEndTea@gmail.com"
                 }
             ],
             "description": "Symfony polyfill for ctype functions",
@@ -6202,16 +6202,16 @@
         },
         {
             "name": "phpunit/phpunit",
-            "version": "7.5.3",
+            "version": "7.5.4",
             "source": {
                 "type": "git",
                 "url": "https://github.com/sebastianbergmann/phpunit.git",
-                "reference": "2cb759721e53bc05f56487f628c6b9fbb6c18746"
+                "reference": "2896657da5fb237bc316bdfc18c2650efeee0dc0"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/2cb759721e53bc05f56487f628c6b9fbb6c18746",
-                "reference": "2cb759721e53bc05f56487f628c6b9fbb6c18746",
+                "url": "https://api.github.com/repos/sebastianbergmann/phpunit/zipball/2896657da5fb237bc316bdfc18c2650efeee0dc0",
+                "reference": "2896657da5fb237bc316bdfc18c2650efeee0dc0",
                 "shasum": ""
             },
             "require": {
@@ -6282,7 +6282,7 @@
                 "testing",
                 "xunit"
             ],
-            "time": "2019-02-01T05:24:07+00:00"
+            "time": "2019-02-07T14:15:04+00:00"
         },
         {
             "name": "sebastian/code-unit-reverse-lookup",