[issue #10] updated transportation widget:

-removed stepAmount variable, because it can be assumed that we have a
proper data set that gives us a reasonable start- and end time and thus
the time period which shall be displayed by the chart; the stepMinutes
variable remains in order to be able to adjust the interval in which the
data is sampled (i.e. 10 min steps)

-removed input fields from widget, as it shall not be configurable by
user

-switched dataSource to a development instance of the icmm service in
order to have proper test data
[issue #10] update:

now there are no more backend calls (to icmm service) in the directive
controller of the transportation chart widget. Requirement therefore is
that the backend call in debriefing view controller returns the full
data (which can be achieved by setting the level parameter in the
get-request (i.e. to the value 5)).