public IServiceProvider ConfigureServices(IServiceCollection services)
        {
            var jwtSettings = Configuration.Get<JwtSettings>();
            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                    .AddJwtBearer(options =>
                    {
                        options.TokenValidationParameters = new TokenValidationParameters
                        {
                            ValidateIssuer = true,
                            ValidateAudience = false,
                            ValidateLifetime = false,
                            ValidateIssuerSigningKey = true,

                            ValidIssuer = jwtSettings.Issuer,
                            IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(jwtSettings.Key))
                        };
                    });

            services.AddMvc();