Update Api Blueprint spec assertions to reflect implementation

Why:
Given specs fails on expecting `description` field being empty while
in current version it contains capitalised version of `name` attribute.
```
       expected: [{:required=>false, :name=>"description", :description=>nil, :properties_description=>"optional"}]
            got: [{:required=>false, :name=>"description", :description=>"Description", :properties_description=>"optional"}]
```

Author: keram

spec/views/api_blueprint_index_spec.rb

@@ -142,7 +142,7 @@
           properties_description: "required, string"
         }, {
           name: "option",
-          description: nil,
+          description: 'Option',
           properties_description: 'optional'
         }]
         expect(post_route_with_optionals[:has_attributes?]).to eq false
@@ -158,7 +158,7 @@
         expect(posts_route[:attributes]).to eq [{
           required: false,
           name: "description",
-          description: nil,
+          description: 'Description',
           properties_description: "optional"
         }]
       end