Added functions for bell states and singlet/triplet states
Fixed bug in triplet_states()
Fixed bug in triplet_states()
resolved merge conflict
Removed states.py from qip module
Removed import qutip.qip.states from __init__.py
Replaced reg_str2array implementation with ket()
Removed utils module from qip
Merge pull request #157 from anubhavvardhan/add_gates

Added functions for bell states and singlet/triplet states