Changelog:
==========
Drop support for Python 3.6. :pr:'262'
Remove soft_unicode, which was previously deprecated. Use soft_str instead. :pr:'261'
Raise error on missing single placeholder during string interpolation. :issue:'225'
Disable speedups module for GraalPython. :issue:'277'
Signed-off-by: Wang Mingyu <wangmy@fujitsu.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
