Prepare release 1.0.6

Add benchmark to measure gc collection of a big chain of cycles (pyth…

…on#243)

Prepare release 1.0.5

Prepare release 1.0.4 (python#129)

Prepare release 1.0.3

Prepare 1.0.2 release

Fix runtests.py

Fix runtests.py: handle FileNotFoundError when removing
pyperformance.egg-info.

Prepare pyperformance 1.0.0 release

prepare 0.9.1 release

Increase version to 0.9 since the project name changed

Prepare 0.9 release.