update release notes

Author: mfeurer

doc/releases.rst

@@ -11,18 +11,20 @@
 Releases
 ========
 
-Version 0.60
+Version 0.6.0
 =============
 
 * MAINT: move from scikit-learn 0.19.X to 0.21.X
 * MAINT #688: allow for pyrfr version 0.8.X
 * FIX #680: Remove unnecessary print statement
+* FIX #600: Remove unnecessary warning
 
 Contributors
 ************
 
 * Guilherme Miotto
 * Matthias Feurer
+* Jin Woo Ahn
 
 Version 0.5.2
 =============