Added MultiThread with DataHolder implementation.
Next implementation will consider concurrent aspects when using the data holder, allowing threads to announce themselves when they start computing some operation, so that no other thread starts doing the same computation in the same time.
Added test for first Computer with Data Holder implementation.

Added MultiThread with DataHolder implementation.
Next implementation will consider concurrent aspects when using the data holder, allowing threads to announce themselves when they start computing some operation, so that no other thread starts doing the same computation in the same time.