Revert setType

Doesn't really belong to this PR

Author: barryvdh

src/phpDocumentor/Reflection/DocBlock/Tag/ReturnTag.php

@@ -60,18 +60,6 @@ public function setContent($content)
         return $this;
     }
 
-    /**
-     * Set the return type
-     *
-     * @param string $type
-     * @return $this
-     */
-    public function setType($type){
-        $this->type = $type;
-        $this->content = null;
-        return $this;
-    }
-
     /**
      * Returns the unique types of the variable.
      *