Class rename, composer add, phpUnit tests add

Rename the class from ReadEnvFile to DotEnv.
Add everything to a composer json file so it can be published to
composer repository.
Add phpUnit tests for system

vendor/phpdocumentor/reflection-common/src/Location.php

@@ -0,0 +1,53 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * This file is part of phpDocumentor.
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ *
+ * @link      http://phpdoc.org
+ */
+
+namespace phpDocumentor\Reflection;
+
+/**
+ * The location where an element occurs within a file.
+ *
+ * @psalm-immutable
+ */
+final class Location
+{
+    /** @var int */
+    private $lineNumber = 0;
+
+    /** @var int */
+    private $columnNumber = 0;
+
+    /**
+     * Initializes the location for an element using its line number in the file and optionally the column number.
+     */
+    public function __construct(int $lineNumber, int $columnNumber = 0)
+    {
+        $this->lineNumber = $lineNumber;
+        $this->columnNumber = $columnNumber;
+    }
+
+    /**
+     * Returns the line number that is covered by this location.
+     */
+    public function getLineNumber() : int
+    {
+        return $this->lineNumber;
+    }
+
+    /**
+     * Returns the column number (character position on a line) for this location object.
+     */
+    public function getColumnNumber() : int
+    {
+        return $this->columnNumber;
+    }
+}