Unable to use grunt-connect-proxy while running Karma

Question

I am trying to execute unit-test using Karma. When I load up the application, the mapping which I have done for the grunt-connect-proxy is been utilized. But while testing, the plugin does not works. I have the following configuration for running the unit-test

grunt.registerTask('unit-test', 'run karma-jasmine unit tests', [
   'clean:server',
   'concurrent:test',
   'autoprefixer',
   'connect:test',
   'karma'
]);

Can anyone help me in making the use of grunt-connect-proxy while executing tests for Karma ?