run custom firefox binary

gistfile1.java

protected WebDriver driver;

    private void startFirefoxDriver() {
        //driver = new FirefoxDriver();
        FirefoxBinary binary = new FirefoxBinary(new File("/Users/username/Downloads/Firefox.app/Contents/MacOS/firefox-bin"));
        FirefoxProfile profile = new FirefoxProfile();
        this.driver = new FirefoxDriver(binary, profile);
    }