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/theseer/tokenizer/tests/TokenizerTest.php

@@ -0,0 +1,21 @@
+<?php declare(strict_types = 1);
+namespace TheSeer\Tokenizer;
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * @covers \TheSeer\Tokenizer\Tokenizer
+ */
+class TokenizerTest extends TestCase {
+
+    public function testValidSourceGetsParsed() {
+        $tokenizer = new Tokenizer();
+        $result = $tokenizer->parse(file_get_contents(__DIR__ . '/_files/test.php'));
+
+        $expected = unserialize(
+            file_get_contents(__DIR__ . '/_files/test.php.tokens'),
+            [TokenCollection::class]
+        );
+        $this->assertEquals($expected, $result);
+    }
+}