Merge pull request #613 from bvssvni/master

Fixed number of colors
Update name in README/Travis link
Merge pull request #614 from maxsnew/master

Update name in README/Travis link
Fix link to online docs

Closes https://github.com/PistonDevelopers/graphics/issues/615
Fixed link to rust-graphics-lab

Closes https://github.com/PistonDevelopers/graphics/issues/616
Pointing "how to contribute" link to piston

Closes https://github.com/PistonDevelopers/graphics/issues/617
Added DeformGrid

Closes https://github.com/PistonDevelopers/graphics/issues/64