Bump version to 4.5.4.

Bump version to 4.5.2.

Bump version number to 4.5.1

Bump version number to 4.5.0

Add `long_description_content_type` to setup.py

Bump version number to 4.3.1

Bump version number to 4.3.0

Bump version number and upload .msi generated by Appveyor to Github.

Fix typo in appveyor.yml

Bump version number to 4.1.3