Log Message:
py-lz4: updated to 2.2.1

v2.2.1:
Update the bundled LZ4 library to version 1.9.1

This release updates the bundled LZ4 library to version 1.9.1.

The 2.2.x releases will be the final release that support Python 2.7. In the \ 
near future we'll begin work on the 3.0.x release which will only support Python \ 
>= 3.5, and will require LZ4 > 1.9.0.

v2.2.0:
Add more detail to the install section of docs