Upgrade phpunit to version 8

Author: coffe4u

.gitignore

@@ -1,3 +1,4 @@
 /.php_cs.cache
+/.phpunit.result.cache
 /composer.lock
 /vendor

composer.json

@@ -20,10 +20,10 @@
         "twilio/sdk": "6.*"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "^1.9",
+        "friendsofphp/php-cs-fixer": "^2.0",
         "illuminate/console": "~4||~5",
         "illuminate/support": "~4||~5",
-        "phpunit/phpunit": "~4.5"
+        "phpunit/phpunit": "~8.0"
     },
     "autoload": {
         "psr-4": {

phpunit.xml

@@ -8,11 +8,10 @@
          convertWarningsToExceptions="true"
          processIsolation="false"
          stopOnFailure="false"
-         syntaxCheck="false"
 >
     <testsuites>
         <testsuite name="Package Test Suite">
             <directory suffix=".php">./tests/</directory>
         </testsuite>
     </testsuites>
-</phpunit>
+</phpunit>

tests/TwilioCallCommandTest.php

@@ -2,17 +2,17 @@
 namespace Aloha\Twilio\Tests;
 
 use Aloha\Twilio\Commands\TwilioCallCommand;
-use PHPUnit_Framework_TestCase;
+use PHPUnit\Framework\TestCase;
 
-class TwilioCallCommandTest extends PHPUnit_Framework_TestCase
+class TwilioCallCommandTest extends TestCase
 {
     /**
      * Test the name of the command
      */
     public function testName()
     {
         // Arrange
-        $stub = $this->getMock('Aloha\Twilio\TwilioInterface');
+        $stub = $this->createMock('Aloha\Twilio\TwilioInterface');
         $command = new TwilioCallCommand($stub);
 
         // Act

tests/TwilioSmsCommandTest.php

@@ -2,17 +2,17 @@
 namespace Aloha\Twilio\Tests;
 
 use Aloha\Twilio\Commands\TwilioSmsCommand;
-use PHPUnit_Framework_TestCase;
+use PHPUnit\Framework\TestCase;
 
-class TwilioSmsCommandTest extends PHPUnit_Framework_TestCase
+class TwilioSmsCommandTest extends TestCase
 {
     /**
      * Test the name of the command
      */
     public function testName()
     {
         // Arrange
-        $stub = $this->getMock('Aloha\Twilio\TwilioInterface');
+        $stub = $this->createMock('Aloha\Twilio\TwilioInterface');
         $command = new TwilioSmsCommand($stub);
 
         // Act