geckodriver.exe not in current directory or path variable, Selenium 2.53.1 + Firefox 48 + Selenium 3 Beta

Try to put the geckodriver.exe in your path: C:\Users\YourName\Documents\Visual Studio 2013\Projects\seleniump\seleniump\bin\Debug

you can find geckodriver.exe at this link:

https://github.com/mozilla/geckodriver/releases