Remove getType() override, add singular_name and plural_name

* REFACTOR: Remove getType() override to allow extensibility

- Removed getType() method override
- Updated $singular_name from 'Testimonials Element' to 'Testimonials'
- Updated $plural_name from 'Testimonials Elements' to 'Testimonials Blocks'

This allows sites to customize the element's display name via extensions
by setting $singular_name.

Fixes #31
Related: dynamic/silverstripe-essentials-tools#68

* Address review: use 'Testimonials' for both singular and plural (collective noun)

Author: jsirish

src/Elements/ElementTestimonials.php

@@ -29,12 +29,12 @@ class ElementTestimonials extends BaseElement
     /**
      * @var string
      */
-    private static $singular_name = 'Testimonials Element';
+    private static $singular_name = 'Testimonials';
 
     /**
      * @var string
      */
-    private static $plural_name = 'Testimonials Elements';
+    private static $plural_name = 'Testimonials';
 
     /**
      * @var string
@@ -95,14 +95,6 @@ protected function provideBlockSchema()
         return $blockSchema;
     }
 
-    /**
-     * @return string
-     */
-    public function getType()
-    {
-        return _t(__CLASS__ . '.BlockType', 'Testimonials');
-    }
-
     /**
      * @return FieldList
      */