Use WP_CLI\Tests\TestCase for better PHP version compat

Author: danielbachhuber

tests/test-arguments.php

@@ -1,7 +1,7 @@
 <?php
 
 use cli\Arguments;
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 
 /**
  * Class TestArguments

tests/test-cli.php

@@ -1,8 +1,7 @@
 <?php
 
 use cli\Colors;
-
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 class testsCli extends TestCase {
 
 	function setUp(): void {

tests/test-colors.php

@@ -1,7 +1,7 @@
 <?php
 
 use cli\Colors;
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 
 class testsColors extends TestCase {
 

tests/test-shell.php

@@ -1,7 +1,7 @@
 <?php
 
 use cli\Shell;
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 
 /**
  * Class TestShell

tests/test-table-ascii.php

@@ -4,7 +4,7 @@
 use cli\Table;
 use cli\table\Ascii;
 use cli\Colors;
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 
 /**
  * Class Test_Table_Ascii

tests/test-table.php

@@ -1,7 +1,7 @@
 <?php
 
 use cli\Colors, cli\Table, cli\Table\Ascii;
-use PHPUnit\Framework\TestCase;
+use WP_CLI\Tests\TestCase;
 
 /**
  * Tests for cli\Table