Fixed bug

Task-Url: http://github.com/asalber/rkTeaching_es/issues/issue/9
Added menu for building a probability space for the repetition of a
experiment

Task-Url: http://github.com/asalber/rkTeaching_es/issues/issue/9
Added menu for calculating probabilities

Task-Url: http://github.com/asalber/rkTeaching_es/issues/issue/9