title: phpunit impossible to follow the installation process
body: <p>I have a lot of problems trying to intall phpunit, maybe my knowledge isn't enought or the guide is very incomplete.</p>
  
  <p>First, the install, I tried all the ways, globally, with "downloaded PHAR file directly" or with "<code>sudo apt-get install phpunit</code>" but when I tried to do:</p>
  
  <pre><code>$phpunit -v
  bash: /usr/bin/phpunit: No chuch file or directory
  </code></pre>
  
  <p>if I do:</p>
  
  <pre><code>$ ll /usr/local/bin (I know, the path is different, other unexplicable event)
  -rwxr-xr-x 1 user user 2784899 abr 29 17:09 phpunit*
  </code></pre>
  
  <p>but</p>
  
  <pre><code>$ sudo phpunit --version
  PHPUnit 7.1.5 by Sebastian Bergmann adn contributors.
  </code></pre>
  
  <p>ok, looks better, so I tried to make the first example</p>
  
  <pre><code>&lt;?php
  use PHPUnit\Framework\TestCase;
  
  class StackTest extends TestCase
  {
      public function testPushAndPop()
      {
          $stack = [];
          $this-&gt;assertSame(0, count($stack));
  
          array_push($stack, 'foo');
          $this-&gt;assertSame('foo', $stack[count($stack)-1]);
          $this-&gt;assertSame(1, count($stack));
  
          $this-&gt;assertSame('foo', array_pop($stack));
          $this-&gt;assertSame(0, count($stack));
      }
  }
  </code></pre>
  
  <p>but it give me the next error:</p>
  
  <pre><code>PHP Fatal error: Class 'PHPUnit\Framework\Testcase' not found in /var/www/html/phpunit/index.php on line 4
  </code></pre>
  
  <p>I'm using Ubuntu 18 and php 7.2</p>
  
  <p>Any idea?</p>