Update changelog with new python additions

CHANGELOG.md

@@ -3,9 +3,12 @@
 ## Unreleased
 
 * pyenv: Migarte project site from https://github.com/yyuu/pyenv to https://github.com/pyenv/pyenv
+* python-build: Add PyPy2 5.7.0 (#872, #868)
+* python-build: Add PyPy3 5.7.0-beta (#871, #869)
+* python-build: Add CPython 3.6.1 (#873)
+* python-build: Add Pyston 0.6.1 (#859)
 * python-build: Change default mirror site URL from https://yyuu.github.io/pythons to https://pyenv.github.io/pythons
 * python-build: Upgrade OpenSSL from 1.0.2g to 1.0.2k (#850)
-* python-build: Add CPython 3.6.1rc1 (#851)
 
 ## 1.0.8