clean up test and update public API

Author: MaggieKimani1

test/Microsoft.OpenApi.Tests/Models/OpenApiInfoTests.cs

@@ -110,7 +110,6 @@ public static IEnumerable<object[]> AdvanceInfoJsonExpect()
                     specVersion,
                     @"{
   ""title"": ""Sample Pet Store App"",
-  ""summary"": ""This is a sample server for a pet store."",
   ""description"": ""This is a sample server for a pet store."",
   ""termsOfService"": ""http://example.com/terms/"",
   ""contact"": {

test/Microsoft.OpenApi.Tests/PublicApi/PublicApi.approved.txt

@@ -1,7 +1,7 @@
 [assembly: System.Reflection.AssemblyMetadata("RepositoryUrl", "https://github.com/Microsoft/OpenAPI.NET")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Microsoft.OpenApi.Readers.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100957cb48387b2a5f54f5ce39255f18f26d32a39990db27cf48737afc6bc62759ba996b8a2bfb675d4e39f3d06ecb55a178b1b4031dcb2a767e29977d88cce864a0d16bfc1b3bebb0edf9fe285f10fffc0a85f93d664fa05af07faa3aad2e545182dbf787e3fd32b56aca95df1a3c4e75dec164a3f1a4c653d971b01ffc39eb3c4")]
 [assembly: System.Runtime.CompilerServices.InternalsVisibleTo(@"Microsoft.OpenApi.Tests, PublicKey=0024000004800000940000000602000000240000525341310004000001000100957cb48387b2a5f54f5ce39255f18f26d32a39990db27cf48737afc6bc62759ba996b8a2bfb675d4e39f3d06ecb55a178b1b4031dcb2a767e29977d88cce864a0d16bfc1b3bebb0edf9fe285f10fffc0a85f93d664fa05af07faa3aad2e545182dbf787e3fd32b56aca95df1a3c4e75dec164a3f1a4c653d971b01ffc39eb3c4")]
-[assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName="")]
+[assembly: System.Runtime.Versioning.TargetFramework(".NETStandard,Version=v2.0", FrameworkDisplayName=".NET Standard 2.0")]
 namespace Microsoft.OpenApi.Any
 {
     public enum AnyType
@@ -424,6 +424,7 @@ namespace Microsoft.OpenApi.Models
         public const string Head = "head";
         public const string Headers = "headers";
         public const string Host = "host";
+        public const string Identifier = "identifier";
         public const string Implicit = "implicit";
         public const string In = "in";
         public const string Info = "info";
@@ -644,6 +645,7 @@ namespace Microsoft.OpenApi.Models
         public OpenApiLicense() { }
         public OpenApiLicense(Microsoft.OpenApi.Models.OpenApiLicense license) { }
         public System.Collections.Generic.IDictionary<string, Microsoft.OpenApi.Interfaces.IOpenApiExtension> Extensions { get; set; }
+        public string Identifier { get; set; }
         public string Name { get; set; }
         public System.Uri Url { get; set; }
         public void SerializeAsV2(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }
@@ -780,13 +782,15 @@ namespace Microsoft.OpenApi.Models
     {
         public OpenApiReference() { }
         public OpenApiReference(Microsoft.OpenApi.Models.OpenApiReference reference) { }
+        public string Description { get; set; }
         public string ExternalResource { get; set; }
         public Microsoft.OpenApi.Models.OpenApiDocument HostDocument { get; set; }
         public string Id { get; set; }
         public bool IsExternal { get; }
         public bool IsLocal { get; }
         public string ReferenceV2 { get; }
         public string ReferenceV3 { get; }
+        public string Summary { get; set; }
         public Microsoft.OpenApi.Models.ReferenceType? Type { get; set; }
         public void SerializeAsV2(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }
         public void SerializeAsV3(Microsoft.OpenApi.Writers.IOpenApiWriter writer) { }