fixes to base.py
Fixes to combinational.py
Merge pull request #235 from debugger22/misc

Miscellaneous fixes based on landscape.io
reset output of gates
reset output of gates
addInput, removeInput functions added
Tests added for logic gates
Merge pull request #237 from salil93/gates

Gates Class improved
Merge branch 'salil93-bus' of https://github.com/rvraghav93/BinPy into salil93-bus