Log Message:
py-lmfit: updated to 0.9.9

Version 0.9.9:
Lmfit now uses the asteval (https://github.com/newville/asteval) package
instead of distributing its own copy. The minimum required asteval version
is 0.9.12, which is available on PyPi. If you see import errors related to
asteval, please make sure that you actually have the latest version installed.