add unit test for license year

Author: pushkyn

test/unit/LicenseYearTest.php

@@ -0,0 +1,22 @@
+<?php
+
+namespace SendGrid\Test;
+
+class LicenseYearTest extends \PHPUnit_Framework_TestCase
+{
+
+    public function testLicenseYear()
+    {
+        $license = explode("\n", file_get_contents('../../LICENSE.txt'));
+        $copyright = '';
+        foreach ($license as $line) {
+            if (strpos($line, 'Copyright') === 0) {
+                $copyright = $line;
+                break;
+            }
+        }
+        $year = date('Y');
+        $expected = "Copyright (c) 2016-{$year} SendGrid, Inc.";
+        $this->assertEquals($expected, $copyright);
+    }
+}