Selenium standalone only works with chrome - selenium

Question

I'm using my protractor tests run with a selenium standalone server.
Now i want to support all browsers.
I created a folder with the standalone (3.0.1) and a subfolder driver with IEDriver, geckodriver, chromedriver.
I added the path to the driver folder to the system PATH.
The standalone is running with no args (i do not know what to add).
My Config is:
var TIMEOUT = 20000;
exports.config = {
seleniumAddress: 'http://localhost:4448/wd/hub',
baseUrl: 'https://intmachine.project.com/',
/*
list the Suites to run locally here
*/
specs: [
'./UseCases/protractorTestcaseNightly.js',
],
capabilities: [
{
'browserName': 'firefox',
'firefox_binary':'C:\\Program Files (x86)\\Mozilla Firefox\\firefox.exe'
// shardTestFiles: false,
// maxInstances: 1,
// maxSessions: -1,
// restartBrowserBetweenTests: true,
},
],
getPageTimeout: TIMEOUT,
allScriptsTimeout: TIMEOUT,
jasmineNodeOpts: {
defaultTimeoutInterval: TIMEOUT,
isVerbose: true,
includeStackTrace: true
},
framework: "jasmine2",
//rootElement: 'html',
onPrepare: function () {
browser.driver.manage().window().maximize();
browser.driver.manage().deleteAllCookies();
}
};
Update:
i changed "Capa..." to capabilities and now get:
[launcher] Running 1 instances of WebDriver
[launcher] Error: TypeError: Target browser must be a string, but is <undefined>; did you forget to call forBrowser()?
at TypeError (native)
at Builder.build (C:\dev\dcps-angular\node_modules\selenium-webdriver\builder.js:417:13)
at DriverProvider.getNewDriver (C:\dev\dcps-angular\node_modules\protractor\built\driverProviders\driverProvider.js:42:27)
at Runner.createBrowser (C:\dev\dcps-angular\node_modules\protractor\built\runner.js:203:37)
at C:\dev\dcps-angular\node_modules\protractor\built\runner.js:293:21
at _fulfilled (C:\dev\dcps-angular\node_modules\q\q.js:834:54)
at self.promiseDispatch.done (C:\dev\dcps-angular\node_modules\q\q.js:863:30)
at Promise.promise.promiseDispatch (C:\dev\dcps-angular\node_modules\q\q.js:796:13)
at C:\dev\dcps-angular\node_modules\q\q.js:556:49
at runSingle (C:\dev\dcps-angular\node_modules\q\q.js:137:13)
[launcher] Process exited with error code 100