Merge pull request #2 from agustinrodriguez/master

Added is_bouncing state and a random final position.
Merge pull request #3 from agustinrodriguez/master

Random spins parameterized.
Renamed roulette to fortune. Added tests
Added new examle
Added tests for unconfigured initialization.
improved tests
Fixed bug when selected price was equal to 0
updated usage description
Moved the arguments to an object to make them clearer
Moved the arguments to an object to make them clearer
Changed default duration to 1 second
Fixed duration time in milliseconds
Added a roulette to test suite
Fixed redeclared variable
Roulette direction parameterized.