[doc] update CHANGELOG

CHANGELOG

 Changelog
 =========
+0.9 (2019-02-01)
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+
+- full python 3.7 syntax support
+
+- BREAKING CHANGE: annotations are now member of {Def,List,Dict}Argument to flatten the data structure, TypedNameNode doesn't exist anymore
+- add support for return annotation by bram
+- add support for variable annotation https://github.com/PyCQA/redbaron/pull/177 by scottbelden and additional work by bram
+- add support for raise from by bram
+
 0.8 (2018-10-29)
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