Delete large 50mb object from IO folder

random_orbit.ogv
Update to gitignore
Rename __Drainage.py to __DrainagePercolation.py
Update to gitignore (I'm updating this file so often I'm beginning to suspect something is going on...)
Merge branch 'master' of https://github.com/PMEAL/OpenPNM
Please don't commit .gitignore. It needs to stay local and specific to each PC. <I think>
Merge branch 'master' of https://github.com/PMEAL/OpenPNM into develop

Conflicts:
	.gitignore