upgrade to karma 0.13

[gruppjo]

We'll have to wait for new release of karma-angular-filesort. wilsonjackson/karma-angular-filesort#1

[gruppjo]

testing.js

var Server = require('karma').Server;

function runKarma (singleRun, done) {
  new Server({
    configFile: path.join(__dirname, '/../karma.conf.js'),
    singleRun: singleRun,
    autoWatch: !singleRun
  }, done).start();
}