Added input verifications

If there's a wrong input it will now ask you again, instead of crashing.
Added validations to initial player choice and pit choice
Merge remote-tracking branch 'origin/master' into ramo-do-tiago
Revert "trying to capture, created inverted function to calculate index, lack of changing the bead in the pit"

This reverts commit e629b94bf8abe8c351cdc5f36bfefa24ccf3fb05.