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/nikic/php-parser/lib/PhpParser/ErrorHandler/Collecting.php

@@ -0,0 +1,46 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\ErrorHandler;
+
+use PhpParser\Error;
+use PhpParser\ErrorHandler;
+
+/**
+ * Error handler that collects all errors into an array.
+ *
+ * This allows graceful handling of errors.
+ */
+class Collecting implements ErrorHandler
+{
+    /** @var Error[] Collected errors */
+    private $errors = [];
+
+    public function handleError(Error $error) {
+        $this->errors[] = $error;
+    }
+
+    /**
+     * Get collected errors.
+     *
+     * @return Error[]
+     */
+    public function getErrors() : array {
+        return $this->errors;
+    }
+
+    /**
+     * Check whether there are any errors.
+     *
+     * @return bool
+     */
+    public function hasErrors() : bool {
+        return !empty($this->errors);
+    }
+
+    /**
+     * Reset/clear collected errors.
+     */
+    public function clearErrors() {
+        $this->errors = [];
+    }
+}

vendor/nikic/php-parser/lib/PhpParser/ErrorHandler/Throwing.php

@@ -0,0 +1,18 @@
+<?php declare(strict_types=1);
+
+namespace PhpParser\ErrorHandler;
+
+use PhpParser\Error;
+use PhpParser\ErrorHandler;
+
+/**
+ * Error handler that handles all errors by throwing them.
+ *
+ * This is the default strategy used by all components.
+ */
+class Throwing implements ErrorHandler
+{
+    public function handleError(Error $error) {
+        throw $error;
+    }
+}