feat(hw3): rename IntegerScanner to GateScanner
feat(hw3): add LogicGate class
feat(hw3): add package name
feat(GateScanner): add readGate and nextGate methods
feat(CircuitTruthTable): implement readInput method
fix(GateScanner): add missing read statement to while loop
fix(GateScanner): throw Exception if unrecognised string is read
feat(CircuitTruthTable): complete implementation