fix(diff): fixed diff status on added required property

A non-required added property in a request should not be reported as a
breaking change.

Fixed the change status of added properties depending on being required
or not in the new specification.

* fixes #2962

Signed-off-by: Frederic BIDON <fredbi@yahoo.com>

Author: fredbi

diff/fixtures/bugs/2962/new.json

@@ -0,0 +1,55 @@
+{
+  "swagger": "2.0",
+  "info": {
+    "title": "Swagger Fixture",
+    "version": "1.0"
+  },
+  "paths": {
+    "/a/{id}": {
+      "post": {
+        "parameters": [
+          {
+            "name": "",
+            "in": "body",
+            "schema": { "$ref": "#/definitions/A2" }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "200 response",
+            "schema": { "$ref": "#/definitions/A3" }
+          }
+        }
+      }
+    }
+  },
+  "definitions": {
+    "A2": {
+      "type": "object",
+      "required": [ "name", "field4" ],
+      "properties": {
+        "name": { "type": "string" },
+        "description": { "type": "string" },
+        "field3": { "type": "string" },
+        "field4": { "type": "string" }
+      }
+    },
+    "A3": {
+      "type": "object",
+      "properties": {
+        "id": { "type": "integer" },
+        "name": { "type": "string" },
+        "otherDeletedName":{"type":"string","deprecated":true},
+        "description": { "type": "string" },
+        "letters": {
+          "type": "array",
+          "items": { "type": "string" }
+        },
+        "attributes": {
+          "type": "object",
+          "additionalProperties": { "type": "string" }
+        }
+      }
+    }
+  }
+}

diff/fixtures/bugs/2962/old.json

@@ -0,0 +1,53 @@
+{
+  "swagger": "2.0",
+  "info": {
+    "title": "Swagger Fixture",
+    "version": "1.0"
+  },
+  "paths": {
+    "/a/{id}": {
+      "post": {
+        "parameters": [
+          {
+            "name": "",
+            "in": "body",
+            "schema": { "$ref": "#/definitions/A2" }
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "200 response",
+            "schema": { "$ref": "#/definitions/A3" }
+          }
+        }
+      }
+    }
+  },
+  "definitions": {
+    "A2": {
+      "type": "object",
+      "required": [ "name", "description" ],
+      "properties": {
+        "name": { "type": "string" },
+        "description": { "type": "string" }
+      }
+    },
+    "A3": {
+      "type": "object",
+      "properties": {
+        "id": { "type": "integer" },
+        "name": { "type": "string" },
+        "otherDeletedName":{"type":"string","deprecated":true},
+        "description": { "type": "string" },
+        "letters": {
+          "type": "array",
+          "items": { "type": "string" }
+        },
+        "attributes": {
+          "type": "object",
+          "additionalProperties": { "type": "string" }
+        }
+      }
+    }
+  }
+}