Remove null default param value

Deprecatation fix

composer.json

@@ -1,12 +1,16 @@
 {
-  "name": "gorriecoe/silverstripe-htmltag",
+  "name": "plato-creative/silverstripe-htmltag",
   "description": "Provides a simply method for wrapping strings with html tags.",
   "type": "silverstripe-vendormodule",
   "license": "BSD-3-Clause",
   "authors": [
     {
       "name": "Gorrie Coe",
       "email": "[email protected]"
+    },
+    {
+      "name": "Plato Creative",
+      "email": "[email protected]"
     }
   ],
   "keywords": [
@@ -15,10 +19,16 @@
     "templates",
     "markup"
   ],
-  "homepage": "http://github.com/gorriecoe/silverstripe-htmltag",
+  "homepage": "http://github.com/PlatoCreative/silverstripe-htmltag",
   "require": {
     "silverstripe/framework": "^4"
   },
+  "repositories": [
+    {
+      "type": "vcs",
+      "url": "https://github.com/PlatoCreative/silverstripe-htmltag"
+    }
+  ],
   "extra": {
     "installer-name": "htmltag"
   }

src/view/HTMLTag.php

@@ -86,7 +86,7 @@ public function setTag($tag)
      * @param string $value Attribute value
      * @return HTMLTag $this
      */
-    public function addAttribute($name = null, $value)
+    public function addAttribute($name, $value)
     {
         if ($value) {
             $this->attributes[$name] = $value;
@@ -97,7 +97,7 @@ public function addAttribute($name = null, $value)
     /**
      * @alias addAttribute
      */
-    public function setAttribute($name = null, $value)
+    public function setAttribute($name, $value)
     {
         $this->addAttribute($name, $value);
         return $this;