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/grammar/README.md

@@ -0,0 +1,30 @@
+What do all those files mean?
+=============================
+
+ * `php5.y`:             PHP 5 grammar written in a pseudo language
+ * `php7.y`:             PHP 7 grammar written in a pseudo language
+ * `tokens.y`:           Tokens definition shared between PHP 5 and PHP 7 grammars
+ * `parser.template`:    A `kmyacc` parser prototype file for PHP
+ * `tokens.template`:    A `kmyacc` prototype file for the `Tokens` class
+ * `rebuildParsers.php`: Preprocesses the grammar and builds the parser using `kmyacc`
+
+.phpy pseudo language
+=====================
+
+The `.y` file is a normal grammar in `kmyacc` (`yacc`) style, with some transformations
+applied to it:
+
+ * Nodes are created using the syntax `Name[..., ...]`. This is transformed into
+   `new Name(..., ..., attributes())`
+ * Some function-like constructs are resolved (see `rebuildParsers.php` for a list)
+
+Building the parser
+===================
+
+Run `php grammar/rebuildParsers.php` to rebuild the parsers. Additional options:
+
+ * The `KMYACC` environment variable can be used to specify an alternative `kmyacc` binary.
+   By default the `phpyacc` dev dependency will be used. To use the original `kmyacc`, you
+   need to compile [moriyoshi's fork](https://github.com/moriyoshi/kmyacc-forked).
+ * The `--debug` option enables emission of debug symbols and creates the `y.output` file.
+ * The `--keep-tmp-grammar` option preserves the preprocessed grammar file.