Scenario template

[nikolayilyin]

We have a minimum set of files required to run beam - a scenario which is good to be used as a template for new city scenarios. It is located in test/input/scenario-template

It is required some improvements:

1. we need to be able to run beam without vehicles.csv file if it is not provided (if it is possible - this file should be removed from the template)
2. we need to be able to run beam without toll-prices file if it is not provided (if it is possible - the file should be removed from the template)
3. add a page into internal wiki with a small description of scenario-template. as a sub-section of generation of new scenario
4. mention in the wiki that there is a benchmark.csv file and this file is used to add a column into reference modeChoice diagram