Added qubits to _init_.py
Switched to tensor function in place of ket
Added method run_state() to use initial state of qubit register
Added not implemented error if state is not defined
Fixed error in docstring
Edited docstring
The values are now user definable
renamed sz to epsmax and sx to deltamax
Optimized the code
Added method to add sub-circuit to the main qubit circuit
Merge pull request #179 from anubhavvardhan/quantum_circuit

Updating qubits.py