Apply fixes from StyleCI (#2)

Author: GrahamCampbell

src/Regex/Result.php

@@ -9,7 +9,7 @@ abstract class Result
      *
      * @return \PhpOption\Option
      */
-    public abstract function success();
+    abstract public function success();
 
     /**
      * Get the error value, if possible.
@@ -28,14 +28,14 @@ public function getSuccess()
      *
      * @return \Dotenv\Regex\Result
      */
-    public abstract function mapSuccess(callable $f);
+    abstract public function mapSuccess(callable $f);
 
     /**
      * Get the error option value.
      *
      * @return \PhpOption\Option
      */
-    public abstract function error();
+    abstract public function error();
 
     /**
      * Get the error value, if possible.
@@ -54,5 +54,5 @@ public function getError()
      *
      * @return \Dotenv\Regex\Result
      */
-    public abstract function mapError(callable $f);
+    abstract public function mapError(callable $f);
 }