v0.7.0-beta

Minor changes:

• Added Aync class for concurrent update of plasticity rules [STDP, IP, iSTDP, SP].
• Updated call for Plasticity methods through Async at Trainer and Simulator

Todo

• I/O bound slows down the simulation. Perform optimization with respect to the number of workers. Otherwise, create an association matrix and do broadcasting over heavyside step func here and here

Version	Iterations	Pool size(ne)	Time(s)
0.6.2	5000	200	166.213
0.7.0	5000	200	179.402

• Notebooks v0.6.2 and v0.7.0