Feature/Add is method to Identifier contract. (#10)

- Now it is possible to use `is()` method to check if two identifiers are the same.

src/Domain/Contracts/Identifier.php

@@ -20,4 +20,13 @@ interface Identifier
      * @return string
      */
     public function value(): string;
+
+    /**
+     * Check if the given identifier is the same than the current one.
+     *
+     * @param  Identifier  $other
+     *
+     * @return bool
+     */
+    public function is(Identifier $other): bool;
 }

src/Domain/ValueObjects/UUIDValue.php

@@ -72,6 +72,18 @@ public static function random(): self
         return new static(self::RANDOM);
     }
 
+    /**
+     * Check if the given identifier is the same than the current one.
+     *
+     * @param  Identifier  $other
+     *
+     * @return bool
+     */
+    public function is(Identifier $other): bool
+    {
+        return $this->equals($other);
+    }
+
     /**
      * To string method.
      *