Add pear modules, mail and net_smtp via composer (#93)

Add pear modules, mail and net_smtp via composer, remove php 5.6 build due to phpunit 6

lib/composer/vendor/sebastian/diff/tests/LineTest.php

@@ -0,0 +1,44 @@
+<?php declare(strict_types=1);
+/*
+ * This file is part of sebastian/diff.
+ *
+ * (c) Sebastian Bergmann <sebastian@phpunit.de>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace SebastianBergmann\Diff;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers SebastianBergmann\Diff\Line
+ */
+final class LineTest extends TestCase
+{
+    /**
+     * @var Line
+     */
+    private $line;
+
+    protected function setUp()
+    {
+        $this->line = new Line;
+    }
+
+    public function testCanBeCreatedWithoutArguments()
+    {
+        $this->assertInstanceOf(Line::class, $this->line);
+    }
+
+    public function testTypeCanBeRetrieved()
+    {
+        $this->assertSame(Line::UNCHANGED, $this->line->getType());
+    }
+
+    public function testContentCanBeRetrieved()
+    {
+        $this->assertSame('', $this->line->getContent());
+    }
+}