Noise

- AppVeyor support for Windows builds (Thanks to Federico Tomassetti)

- Fix MSVC compatibility (Thanks to Christoph Gohlke)

- Add lacunarity parameter for perlin and simplex functions

- Add 4D simplex noise

- 2D simplex noise can now be tiled seamlessly

- Fixed artifact in 3D simplex noise output

- Updated animate_tex example to use simplex noise

- Updated 2dtexture example to work with Python 3 and use simplex noise

- Fix shaders to work with Python 3

- Pretty up the atmosphere shader noise example.

- Improve lighting/brightness of planet example.

- Fixed C-extensions to build in Python 3.

- Fixed broken 3D simplex noise implementation.

- Add kwarg support to simplex noise functions

- Fixed range of 3D simplex noise with multiple octaves

- Fixed crash in perlin noise due to index out of range

- Added unit tests

- Moved code to github