Circuit model basic implementation

[BenjaminCarpenter480]

Allows creation of a matrix representing a quantum circuit that uses Hadamard and Not gates. Won't work for more complex gates such as controlled not.

TODO:

• [ ] Measuring the result
• [ ] Creating a quantum circuit for more than Hadamard and Not gates
• [ ] Quantum register class
• [ ] Gates constructor checking correct properties
• [ ] Look through todo's on various classes
• [ ] Improve documentation