[Register] Quantum Register

[Roger-luo]

Register is something contains a quantum states. Since a quantum state of N qubits is actually a rank-N tensor. All quantum registers supports the interface of julia arrays.

To preserve memory contiguous, we use the last dimension as our batch dimension. An naive implementation could be

struct Register{M, B, T, N} <: AbstractRegister{M, B, T, N}
    data::Array{T, N}
end

where M is the number of qubits, and B is the number of batches.

[Roger-luo]

Done #10