Bump version to 1.3 (#26)

Bump version (#23)

v1.1 version bump, and add more documentation examples (#19)

Version 1.0

Add IGDWriter, IGDFile->IGDReader, and add IGDTransformer (#5)

* Add IGD writing capability, IGDTransformer
* IGDFile is now IGDReader, and takes an IO buffer instead of a filename. This is more flexible, and removes the need to have a context manager. IGDFile remains, but will be removed soon and should be avoided.
* IGDWriter is new: create IGD files in Python.
* IGDTransformer lets you take an input IGD buffer and modify the sample information, producing a new output IGD buffer.
* Documentation and examples
* Make flake8 happy, fix test dependencies
* Bump version

Add pyproject.yoml and update README to reflect pypi support

You can now install via `pip install pyigd`